Add event calendar and update site content

Add a calendar page and ICS file for event subscriptions. Update the
Hello Linux presentation with Tux images and add setup instructions
to the README.

README.md

@@ -1,3 +1,19 @@
 # Faux Linux User Group presentations
 
 This repository contains the FLUG presentations.
+
+## Usage
+
+Install the required dependencies:
+
+```bash
+nvm use stable
+npm install
+npm install -g vite
+```
+
+Run the development server:
+
+```bash
+vite
+```