Remove remnants of /guides directory (#6333)

Finalizes the work completed as part of
#5767, removing the
remaining mentions of the `/guides` directory. Adds a new
[`https://dart.dev/docs`](https://dart-dev--pr6333-feat-remove-guides-directory-gf8u03iz.web.app/docs)
page to act as an index into our documentation.

Follow up PRs will adjust and expand the index.

Closes #5767

firebase.json

@@ -151,7 +151,6 @@
       { "source": "/docs/tutorials/shared-pkgs", "destination": "/tools/pub/packages", "type": 301 },
       { "source": "/docs/tutorials/streams", "destination": "/libraries/async/using-streams", "type": 301 },
       { "source": "/docs/tutorials{,/**}", "destination": "/tutorials", "type": 301 },
-      { "source": "/docs{,/**}", "destination": "/guides", "type": 301 },
       { "source": "/downloads{,/**}", "destination": "/get-dart", "type": 301 },
       { "source": "/eclipse{,/**}", "destination": "/tools#editors", "type": 301 },
       { "source": "/editor{,/**}", "destination": "/tools#editors", "type": 301 },
@@ -179,7 +178,7 @@
       { "source": "/go/flutter-upper-bound-deprecation", "destination": "https://github.com/flutter/flutter/issues/68143", "type": 301 },
       { "source": "/go/macros", "destination": "/language/macros", "type": 301 },
       { "source": "/go/pub-workspaces", "destination": "/tools/pub/workspaces", "type": 301 },
-      { "source": "/go/workspaces-stray-files", "destination": "/guides/workspaces#stray-files", "type": 301 },
+      { "source": "/go/workspaces-stray-files", "destination": "/tools/pub/workspaces#stray-files", "type": 301 },
       { "source": "/go/non-promo-conflicting-getter", "destination": "/tools/non-promotion-reasons#getter-name", "type": 301 },
       { "source": "/go/non-promo-conflicting-non-promotable-field", "destination": "/tools/non-promotion-reasons#field-name", "type": 301 },
       { "source": "/go/non-promo-conflicting-noSuchMethod-forwarder", "destination": "/tools/non-promotion-reasons#nosuchmethod", "type": 301 },
@@ -209,6 +208,7 @@
       { "source": "/go/unsound-null-safety", "destination": "/null-safety/unsound-null-safety", "type": 301 },
 
       { "source": "/googleapis", "destination": "https://github.com/dart-lang/googleapis", "type": 301 },
+      { "source": "/guides{,/**}", "destination": "/docs", "type": 301 },
       { "source": "/guides/environment-declarations", "destination": "/libraries/core/environment-declarations", "type": 301 },
       { "source": "/guides/get-started", "destination": "/overview", "type": 301 },
       { "source": "/guides/google-apis", "destination": "/resources/google-apis", "type": 301 },
@@ -251,6 +251,7 @@
       { "source": "/guides/platforms", "destination": "/overview#platform", "type": 301 },
       { "source": "/guides/testing", "destination": "/tools/testing", "type": 301 },
       { "source": "/guides/whats-new", "destination": "/resources/whats-new", "type": 301 },
+      { "source": "/guides/workspaces", "destination": "/tools/pub/workspaces", "type": 301 },
       { "source": "/install", "destination": "/get-dart", "type": 301 },
       { "source": "/install/**", "destination": "/get-dart", "type": 301 },
       { "source": "/install/archive", "destination": "/get-dart/archive", "type": 301 },

src/_includes/navigation-main.html

@@ -14,8 +14,8 @@
         {%- if page_url_path contains '/*/overview/' %} active {%- endif -%}">Overview</a>
     </li>
     <li class="mainnav__get-started">
-      <a href="/guides" class="nav-link
-        {%- if page_url_path contains '/*/guides/' or page_url_path contains '/*/language/' or page_url_path contains '/*/resources/' or page_url_path contains '/*/codelabs/' or page_url_path contains '/*/deprecated/' or page_url_path contains '/*/tools/' or page_url_path contains '/*/tutorials/' or page_url_path contains '/*/server/' or page_url_path contains '/*/web/' or page_url_path contains '/*/effective-dart/' or page_url_path contains '/*/libraries/' %} active {%- endif -%}">
+      <a href="/docs" class="nav-link
+        {%- if page_url_path contains '/*/docs/' or page_url_path contains '/*/language/' or page_url_path contains '/*/resources/' or page_url_path contains '/*/codelabs/' or page_url_path contains '/*/deprecated/' or page_url_path contains '/*/tools/' or page_url_path contains '/*/tutorials/' or page_url_path contains '/*/server/' or page_url_path contains '/*/web/' or page_url_path contains '/*/effective-dart/' or page_url_path contains '/*/libraries/' %} active {%- endif -%}">
         <span>Docs</span>
       </a>
     </li>

src/_includes/navigation-side.html

@@ -19,7 +19,7 @@
         <a href="/get-dart" class="nav-link">Get Dart</a>
       </li>
       <li class="nav-item">
-        <a href="/guides" class="nav-link">Docs</a>
+        <a href="/docs" class="nav-link">Docs</a>
       </li>
       <li aria-hidden="true"><div class="sidebar-primary-divider"></div></li>
     </ul>

src/content/guides/index.md → src/content/docs.md

@@ -18,8 +18,6 @@ To update these cards, edit src/_data/docs_cards.yml.
 
 <div class="card-grid">
 {% for card in docs_cards -%}
-  {% capture index0Modulo3 %}{{ forloop.index0 | modulo:3 }}{% endcapture %}
-  {% capture indexModulo3 %}{{ forloop.index | modulo:3 }}{% endcapture %}
   <div class="card">
     <h2><a href="{{card.url}}">{{card.name}}</a></h2>
     <p>{{card.description}}</p>

src/content/libraries/dart-core.md

@@ -1080,7 +1080,7 @@ Support for weak references and finalizers was added in Dart 2.17.
 [Uri]: {{site.dart-api}}/dart-core/Uri-class.html
 [WeakReference]: {{site.dart-api}}/dart-core/WeakReference-class.html
 [dart:core]: {{site.dart-api}}/dart-core/dart-core-library.html
-[dart:ffi]: /guides/libraries/c-interop
+[dart:ffi]: /interop/c-interop
 [double]: {{site.dart-api}}/dart-core/double-class.html
 [garbage-collected]: https://medium.com/flutter/flutter-dont-fear-the-garbage-collector-d69b3ff1ca30
 [int]: {{site.dart-api}}/dart-core/int-class.html

src/content/resources/breaking-changes.md

@@ -111,7 +111,7 @@ accounting for them before the 3.7 release.
   All usages should be migrated to the new `--page-width` option.
 
 [new style]: {{site.repo.dart.org}}/dart_style/issues/1253
-[language version]: /guides/language/evolution#language-versioning
+[language version]: /resources/language/evolution#language-versioning
 [configure your analysis options]: /tools/analysis
 [`dart fix`]: /tools/dart-fix
 
@@ -664,7 +664,7 @@ on all the changes in this section.
 [collection]: /resources/dart-3-migration#dart-collection
 [49529]: {{site.repo.dart.sdk}}/issues/49529
 [`DeferredLibrary`]: {{site.dart-api}}/stable/2.18.4/dart-async/DeferredLibrary-class.html
-[`deferred as`]: /guides/language/language-tour#lazily-loading-a-library
+[`deferred as`]: /language/libraries#lazily-loading-a-library
 [`MAX_USER_TAGS`]: {{site.dart-api}}/stable/dart-developer/UserTag/MAX_USER_TAGS-constant.html
 [`maxUserTags`]: {{site.dart-api}}/beta/2.19.0-255.2.beta/dart-developer/UserTag/maxUserTags-constant.html
 [50231]: {{site.repo.dart.sdk}}/issues/50231
@@ -1281,5 +1281,5 @@ other.
 * Replaced pub's transformer-based build system with a [new build system][build system].
 
 [30345]: {{site.repo.dart.sdk}}/issues/30345
-[strong mode]: /guides/language/type-system
+[strong mode]: /language/type-system
 [build system]: {{site.repo.dart.org}}/build

src/content/resources/coming-from/swift-to-dart.md

@@ -2828,6 +2828,6 @@ multiplatform applications from a single codebase),
 where you'll find in-depth information about the
 language and practical ways of getting started. 
 
-[Dart]: /guides
+[Dart]: /docs
 [Flutter]: {{site.flutter-docs}}