Add new templates and tests for improved functionality

- Created index.html template for the homepage with service cards and partner logos.
- Added page_from_md.html template for rendering pages from markdown.
- Developed services.html template detailing various services offered.
- Implemented tests for link handling in markdown, ensuring external links open in new tabs and internal links function correctly.
- Enhanced markdown parser tests to validate heading extraction, content rendering, and link safety.
- Introduced utility tests for template rendering, HTML minification, and JavaScript minification.

Co-authored-by: Copilot <copilot@github.com>

html/img/security.svg

@@ -0,0 +1,10 @@
+<svg 
+    xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" 
+    stroke="rgb(37 99 235 / var(--tw-text-opacity, 1))" 
+    stroke-width="2" 
+    stroke-linecap="round" 
+    stroke-linejoin="round"
+>
+    <rect width="18" height="11" x="3" y="11" rx="2" ry="2"></rect>
+    <path d="M7 11V7a5 5 0 0 1 10 0v4"></path>
+</svg>