Rename file and update README

doc/api/README.md

@@ -43,6 +43,7 @@ following locations:
 - [Tags](tags.md)
 - [Todos](todos.md)
 - [Users](users.md)
+- [Validate CI configuration](ci/lint.md)
 ### Internal CI API
@@ -50,7 +51,6 @@ The following documentation is for the [internal CI API](ci/README.md):
 - [Builds](ci/builds.md)
 - [Runners](ci/runners.md)
-- [Validate the .gitlab-ci.yaml](ci/ci_lint.md)
 ## Authentication

doc/api/ci/README.md

@@ -22,4 +22,3 @@ GET /ci/api/v1/builds/:id/artifacts
 - [Builds](builds.md)
 - [Runners](runners.md)
-- [Validate the .gitlab-ci.yaml](ci_lint.md)

doc/api/ci/ci_lint.md → doc/api/ci/lint.md

-# Validate the .gitlab-ci.yaml
+# Validate the .gitlab-ci.yml
 Check whether your .gitlab-ci.yml file is valid.