url: fix matching ~, $VAR, .directory/

Related to #1972

This commit adds three new alternatives for
`rooted_or_relative_path_prefix`:

- `~/`
- `$VAR` and
- `.local/`, `.config/` etc. for dot-prefixed directory names

src/config/url.zig

@@ -75,7 +75,7 @@ const scheme_url_branch =
     no_trailing_punctuation;
 
 const rooted_or_relative_path_prefix =
-    \\(?:\.\.\/|\.\/|(?<!\w)\/)
+    \\(?:\.\.\/|\.\/|~\/|\$\w+\/|\.[\w][\w\-.]*\/|(?<!\w)\/)
 ;
 
 // Branch 2: Absolute paths and dot-relative paths (/, ./, ../).