Improved the static assets definitions in the Website service (#18)

This PR contains the work done to overhaul the static asset definitions for the Website service.

To provide further details about the work:

* Website library
  * Overhauled the `StateFile` enumeration to reduce the number of cases to one case per logical file name, each exposing a `fileExtensions` list.
  * Wired everything into the pages with a consistent ordering convention: stylesheets load shared-first so the page sheet wins the CSS cascade; scripts load page-first with shared.js last. The error page also gained the shared stylesheet and its scripts; the index page gained its page CSS/JS and the new touch icon link.
  * Used the `StaticFile` enumeration as a single source of truth for every _href_/_src_ in the `IndexPage` and the `ErrorPage` pages, eliminating hardcoded asset paths.

* Website service
  * Added new assets to the Resources folder:
    * `apple-touch-icon.png`
    * `css/index.css`
    * `js/index.js`
    * `js/error.js`
    * `sitemap.xml`
  * Renamed existing assets within the Resources folder:
    * `css/style.css` → `css/shared.css`
    * `js/app.js` → `js/shared.js`
  * Fixed the working-directory location for the scheme in the Xcode project.

Reviewed-on: rock-n-code/loud-amsterdam#18
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>

Services/Website/Sources/Library/Internal/Pages/IndexPage.swift

@@ -26,12 +26,13 @@ struct IndexPage: HTMLDocument, Sendable {
 
     // MARK: Document
 
-    /// The page's content: a localized greeting followed by the app script.
+    /// The page's content: a localized greeting followed by the shared and index scripts.
     var body: some HTML {
         p {
             localize("index.greeting", locale: locale)
         }
-        script(.src("/js/app.js")) {}
+        script(.src(StaticFile.index.urlPath(for: .js))) {}
+        script(.src(StaticFile.shared.urlPath(for: .js))) {}
     }
 
     /// The metadata, stylesheet, icon, and manifest links placed in the document head.
@@ -43,11 +44,15 @@ struct IndexPage: HTMLDocument, Sendable {
         )
         link(
             .rel(.stylesheet),
-            .href("/css/style.css")
+            .href(StaticFile.shared.urlPath(for: .css))
+        )
+        link(
+            .rel(.stylesheet),
+            .href(StaticFile.index.urlPath(for: .css))
         )
         link(
             .rel(.icon),
-            .href("/favicon.ico"),
+            .href(StaticFile.favicon.urlPath(for: .ico)),
             .custom(
                 name: "sizes",
                 value: "any"
@@ -55,7 +60,7 @@ struct IndexPage: HTMLDocument, Sendable {
         )
         link(
             .rel(.icon),
-            .href("/icon.svg"),
+            .href(StaticFile.icon.urlPath(for: .svg)),
             .custom(
                 name: "type",
                 value: "image/svg+xml"
@@ -63,11 +68,11 @@ struct IndexPage: HTMLDocument, Sendable {
         )
         link(
             .rel("apple-touch-icon"),
-            .href("/icon.png")
+            .href(StaticFile.appleTouchIcon.urlPath(for: .png))
         )
         link(
             .rel("manifest"),
-            .href("/site.webmanifest")
+            .href(StaticFile.site.urlPath(for: .webmanifest))
         )
         meta(
             .name("theme-color"),