Add yamllint (#26965)

So that https://github.com/go-gitea/gitea/pull/26964 does not happen
again. Merge this after that PR. Config is based on
[node's](https://github.com/nodejs/node/blob/main/.yamllint.yaml).

---------

Co-authored-by: techknowlogick <techknowlogick@gitea.com>

.eslintrc.yaml

@@ -156,7 +156,7 @@ rules:
   import/no-restricted-paths: [0]
   import/no-self-import: [2]
   import/no-unassigned-import: [0]
-  import/no-unresolved: [2, {commonjs: true, ignore: [\?.+$, ^vitest/]}]
+  import/no-unresolved: [2, {commonjs: true, ignore: ["\\?.+$", ^vitest/]}]
   import/no-unused-modules: [2, {unusedExports: true}]
   import/no-useless-path-segments: [2, {commonjs: true}]
   import/no-webpack-loader-syntax: [2]