Update doc preview infrastructure

Align the used NodeJS and Ruby versions and scripts with the website build.

Signed-off-by: Florian Hotze <florianh_dev@icloud.com>

.nvmrc

@@ -0,0 +1 @@
+16.20.1

.ruby-version

@@ -0,0 +1 @@
+3.3.2

.vuepress/add_placeholders.rb

@@ -1,7 +1,7 @@
 # This function will add placeholders for pages that are out of scope of the docs preview
 
 def add_placeholder_pages()
-    puts ">>> Adding placeholder pages for preview"
+    puts "➡️ Adding placeholder pages for preview"
     [
         "addons/integrations/homekit",
         "addons/integrations/openhabcloud",
@@ -19,7 +19,7 @@ def add_placeholder_pages()
         "docs/ecosystem/mycroft",
         "docs/installation/openhabian.md"
     ].each { |path|
-        puts " -> #{path}"
+        puts "  ➡️ #{path}"
         page = path
         if (!(path =~ /\.md/)) then
             FileUtils.mkdir_p(path)

.vuepress/config.ts

@@ -7,7 +7,7 @@ const base = process.env.OH_DOCS_VERSION
     : '/'
 
 const config: UserConfig<DefaultThemeConfig> = {
-    title: 'v4 Documentation Preview',
+    title: 'Documentation Preview',
     description: 'This is a preview of the main parts of the documentation, found in the openhab/openhab-docs repository',
     dest: 'vuepress',
     host: 'localhost',

README.md

@@ -81,33 +81,32 @@ The new build will include all the latest changes in the code repository and in
 
 ### How to build the documentation locally
 
-It is possible to build a preview version of the documentation on your local machine. The following software is required:
-
-- [`node =16.20.1`](https://nodejs.org/en)
-- [`ruby >=3.0.2`](https://www.ruby-lang.org/en/)
-- [`Python >= 3.10.12`](https://www.python.org)
-
-If you work on multiple node projects [Node Version Manager](https://github.com/nvm-sh/nvm) is recommended in case they use a different version of node.
-
-Example:
-
-```bash
-$ nvm install 16
-# ...
-$ nvm use 16
-Now using node v16.20.2 (npm v8.19.4)
-$ npm install
-# ...
-$ npm run serve
-# ...
-Serving HTTP on 0.0.0.0 port 8000 (http://0.0.0.0:8000/)
+It is possible to build a preview version of the documentation on your local machine.
+The following software is required:
+
+- [`NodeJS = 16.20.1`](https://nodejs.org/en)
+- [`Ruby >= 3.3.2`](https://www.ruby-lang.org/en/)
+
+We recommend to use [Node Version Manager](https://github.com/nvm-sh/nvm) as well as [Ruby Version Manager](https://rvm.io/) to easily allow using multiple versions of NodeJS and Ruby for multiple projects.
+If you don't do that, you can simply start by only installing the above mentioned versions.
+
+When using `nvm` and/or `rvm`, setup the NodeJS and/or Ruby version:
+
+```shell script
+nvm use
+rvm use
+```
+
+Next, you can build & serve the documentation preview:
+
+```shell script
+npm run serve-preview
 ```
 
-The local preview is available under the following options
+The local preview is available under the following URLs:
 
-- [http://0.0.0.0:8000/docs](http://0.0.0.0:8000/docs)
-- [http://localhost:8000/docs](http://localhost:8000/docs)
-- [http://[::]/:8000/docs](http://[::]:8000/docs)
+- <http://0.0.0.0:8080/docs>
+- <http://localhost:8080/docs>
 
 ![local preview](images/local-docu-preview.png)