✨♻️💄 app, frontend, README: Update content, theme handling, and styles

- Added `Codeberg` link to contact page in `contact.rs`
- Removed `Auto` theme option and set `Dark` as default in `theme_switcher`
- Updated biography text and link formatting in `HomePage` component
- Simplified theme CSS structure and adjusted color variables in `styles.css`
- Removed outdated SHA256 warning and added `Cargo.toml` note in `README.md`

crates/app/src/lib.rs

@@ -124,6 +124,7 @@ pub fn App() -> impl IntoView {
 #[component]
 fn Root(children: Children) -> impl IntoView {
     view! { <div id="root">{children()}</div> }
+    // view! { {children()} }
 }
 
 #[component]
@@ -134,9 +135,11 @@ fn NotFound() -> impl IntoView {
 #[component]
 fn HomePage() -> impl IntoView {
     view! {
-        <p>"Hi. I'm Markus. I mostly do full stack development with Rust and Nix."</p>
+        <p>"Hi. I'm Markus. I'm a software engineer currently doing mostly full stack development with Rust and Nix."</p>
         <p>
-            "You can check out some of my projects "<A href="/projects">"here"</A>" or on my "<A href="https://git.mascully.com/mascully?tab=repositories">"Git forge"</A>", including the "
+            "You can check out some of my projects "<A href="/projects">"here"</A>" or on my "
+            <A href="https://git.mascully.com/mascully?tab=repositories">"Git forge"</A>
+            ", including the "
             <A href="https://git.mascully.com/mascully/mascully_website">
                 "source code for this website"
             </A>"."