Updated "getting started" with more installation instructions

docs/user-manual/getting-started.md

@@ -1,6 +1,20 @@
 # Getting started
 
-Install the extension from the [Visual Studio marketplace](https://marketplace.visualstudio.com/items?itemName=SpontanCombust.witcherscript-ide) or [Open VSX](https://open-vsx.org/extension/SpontanCombust/witcherscript-ide) if you're using other VSCode variants. You can also grab a .vsix file directly from the [releases](https://github.com/SpontanCombust/witcherscript-ide/releases) page.
+## Installation
+
+Install the extension from the [Visual Studio marketplace](https://marketplace.visualstudio.com/items?itemName=SpontanCombust.witcherscript-ide) or [Open VSX](https://open-vsx.org/extension/SpontanCombust/witcherscript-ide) if you're using other VSCode variants. 
+
+You can also grab a .vsix file directly from the [releases](https://github.com/SpontanCombust/witcherscript-ide/releases) page. To install the extension manually:
+
+1. Open VS Code
+2. Open "Extensions" view
+3. Click on the tree dots in the upper-right corner of the view and select "Install from VSIX..."
+4. Alternatively you can use the command palette (<nobr>`LCtrl + LShift + P`</nobr>) and search for "Extensions: Install from VSIX..."
+5. Select downloaded VSIX file and the new extension version should get installed!
+
+Pre-release versions of WIDE are also available, but for now only through GitHub's releases page due to versioning system limitations forced by the marketplace.
+
+## Tutorial
 
 WIDE's VSCode extension comes with a quick walkthrough that will guide you through necessary steps to make it work. If you can't find the walkthrough use the command `"Welcome: Open Walkthrough..."` in the command palette and search for WitcherScript IDE.