chore: update README structure and markdownlint configuration (#180)

This PR reorganizes the awesome list in README.md by maintenance status: Active projects, Unmaintained, and Archived.
It also updates the table of contents and moves previously symbol-tagged entries into their matching sections for better readability.
Finally, .markdownlint.yaml disables MD024 to allow repeated subsection headings across those status groups.

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Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-on: https://gitea.com/gitea/awesome-gitea/pulls/180
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Nicolas <bircni@icloud.com>
Co-committed-by: Nicolas <bircni@icloud.com>

.markdownlint.yaml

@@ -6,7 +6,8 @@ line-length: {code_blocks: false, tables: false, stern: true, line_length: -1}
 no-alt-text: false
 no-bare-urls: false
 no-blanks-blockquote: false
-no-duplicate-header: {allow_different_nesting: true}
+# Parallel Active / Unmaintained / Archived blocks reuse subsection titles (e.g. "Applications").
+MD024: false
 no-emphasis-as-header: false
 no-empty-links: false
 no-hard-tabs: {code_blocks: false}