Add link tester to CI (#164)

For this repository, I wrote a small Github Action to check the validity of links.

https://github.com/marketplace/actions/links-check-action

Demo on [my Gitea instance](https://git.zetcraft.ru/serega404/awesome-gitea/actions/runs/19)
Demo on [Github](https://github.com/serega404/awesome-gitea/actions/runs/16038610102/job/45255671331)

Output example:
<img width="1420" alt="image.png" src="attachments/5364cf47-8606-4f2d-bd78-03da442cef8b">

Reviewed-on: https://gitea.com/gitea/awesome-gitea/pulls/164
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Sergey Karmanov <ppoocpel8888@gmail.com>
Co-committed-by: Sergey Karmanov <ppoocpel8888@gmail.com>

.gitea/workflows/testlinks.yml

@@ -0,0 +1,16 @@
+name: Test links
+on:
+  - push
+  - pull_request
+
+jobs:
+  check_urls:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+      - name: Link check action
+        uses: serega404/links-check-action@v0.0.1
+        with:
+          filePath: "README.md"
+          ignoreCodes: "403,418"

README.md

@@ -42,7 +42,6 @@ A curated list of awesome projects related to Gitea and its soft-fork instances.
 
 ### Bot
 
-- [giteacat](https://git.mastodont.cat/spla/giteacat.git) - Python Bot that register Mastodon server's users to Gitea instance, on demand.
 - [gopher-bot](https://github.com/nfort/gopher-bot) - Bot for checking golang code
 - [issue-bot](https://git.meli.delivery/meli/issue-bot) - Bot for mailing list mirroring of Gitea issues. Allow people to submit issues on repositories using only e-mail without signing up. [github read-only mirror](https://github.com/meli/issue-bot)
 - [sq-bot](https://codeberg.org/justusbunsi/gitea-sonarqube-bot) - Bot for decorating Gitea pull requests with SonarQube analysis details.
@@ -85,7 +84,7 @@ A curated list of awesome projects related to Gitea and its soft-fork instances.
 - [watchtower](https://github.com/containrrr/watchtower) - A process for automating Docker container base image updates. Useful for running Continuous Deployment pipeline steps.
 - [webhook](https://github.com/adnanh/webhook) - webhook is a lightweight incoming webhook server to run shell commands. Useful for running Continuous Deployment pipeline steps.
 - [webhookd](https://github.com/ncarlier/webhookd) - A very simple webhook server launching shell scripts. Useful for running Continuous Deployment pipeline steps.
-- [woodpecker](https://github.com/woodpecker-ci/woodpecker) - An opinionated fork of the Drone CI system. Built-in Gitea support. (see [docs](https://woodpecker-ci.org/docs/administration/vcs/gitea))
+- [woodpecker](https://github.com/woodpecker-ci/woodpecker) - An opinionated fork of the Drone CI system. Built-in Gitea support. (see [docs](https://woodpecker-ci.org/docs/administration/configuration/forges/gitea))
 - [yojo](https://sr.ht/~emersion/yojo/) - A CI bridge from Gitea to SourceHut.
 
 ### Mobile
@@ -123,7 +122,6 @@ A curated list of awesome projects related to Gitea and its soft-fork instances.
 
 - [Codeberg](https://codeberg.org/Codeberg) - Non-Profit Collaboration Community for Free and Open Source Projects (formerly known under its working title teahub.io).
 - [Disroot](https://git.disroot.org/) - Aims to change the way people are used to interact on the web.
-- [GitShuiShan](http://gitea.shuishan.net.cn/) - A Git platform for education
 - [OpenDev](https://opendev.org/) - A space for collaborative Open Source software development.
 - [RadioRepo](https://repo.radio/) - The home of software development for the Amateur Radio Community.
 - [~vern gitea](https://git.vern.cc/) - A gitea instance for free software hackers
@@ -131,11 +129,10 @@ A curated list of awesome projects related to Gitea and its soft-fork instances.
 ### For internal use
 
 - [Blender](https://projects.blender.org) - The Blender Projects portal where all the (Blender) official initiatives are coordinated and managed.
+- [openSUSE](https://src.opensuse.org/) - openSUSE Gitea
 - [FSFE](https://git.fsfe.org/) - Git @ Free Software Foundation Europe
-- [openSUSE](https://gitea.opensuse.org/) - openSUSE Gitea
 - [PSES](https://git.passageenseine.fr/pses) - Git @ Pas Sage en Seine.
 - [Sum7](https://dev.sum7.eu/) - A hoster to support decentralized services. A step away from big cloud services.
-- [Teknik](https://git.teknik.io/Teknikode) - Provide services to help those who try to innovate.
 
 ## Packages
 
@@ -216,7 +213,6 @@ A curated list of awesome projects related to Gitea and its soft-fork instances.
 - [Dark Arc](https://github.com/Jieiku/theme-dark-arc-gitea) - Dark theme with high contrast, based on arc-green.
 - [Dark Blue](https://gitea.artixlinux.org/artix/gitea-dark-blue) - The dark blue Gitea theme used on [https://gitea.artixlinux.org](https://gitea.artixlinux.org)
 - [Dark Red](https://github.com/iamdoubz/Gitea-Dark-Red-Theme) - Dark red theme by iamdoubz
-- [Deep Dark](https://github.com/plashenkov/gitea-theme-deep-dark) - A deep dark theme based on arc-green and featuring unified headers.
 - [Earl Grey](https://github.com/Troplo/earl-grey) - An elegant dark theme for Gitea with blue as the primary color.
 - [GitHub](https://github.com/Rainnny7/gitea-github-theme) - A theme to make Gitea look and feel like GitHub.
 - [GitHub Dark](https://github.com/lutinglt/gitea-github-theme) - A dark theme to make Gitea look and feel like GitHub.