Refactor Paper Tonic Modern colorscheme and enhance semantic highlighting

- Updated highlights.scm to improve CSS, HTML, and data attribute captures with higher priority.
- Added a new Lua function to display highlight group and color information under the cursor.
- Expanded editor, semantic, syntax, and TreeSitter highlight groups for better visual consistency across languages.
- Created test files for PHP, HTML, CSS, and Lua to validate syntax highlighting.
- Implemented a shell script to test semantic highlights in a Neovim session.
- Simplified colorscheme loading process by removing unnecessary plugin specifications.

test-standalone.css

@@ -0,0 +1,11 @@
+.test-class {
+    color: red;
+}
+
+#test-id {
+    background: blue;
+}
+
+.another:hover {
+    border: 1px solid green;
+}