ci: reenable link checker & fix broken links (#15489)

Follow-up on #15484.

.github/.linkspector.yml

@@ -1,9 +1,22 @@
 dirs:
   - docs
+excludedDirs:
+  # Downstream bug in linkspector means large markdown files fail to parse
+  # but these are autogenerated and shouldn't need checking
+  - docs/reference
+  # Older changelogs may contain broken links
+  - docs/changelogs
 ignorePatterns:
-  - pattern: "://localhost"
-  - pattern: '://.*.?example\\.com'
-  - pattern: "github.com/<your_github_handle>"
+  - pattern: "localhost"
+  - pattern: "example.com"
   - pattern: "mailto:"
+  - pattern: "127.0.0.1"
+  - pattern: "0.0.0.0"
+  - pattern: "JFROG_URL"
+  - pattern: "coder.company.org"
+  # These real sites were blocking the linkspector action / GitHub runner IPs(?)
+  - pattern: "i.imgur.com"
+  - pattern: "code.visualstudio.com"
+  - pattern: "www.emacswiki.org"
 aliveStatusCodes:
   - 200

.github/workflows/weekly-docs.yaml

@@ -4,11 +4,11 @@ on:
   schedule:
     - cron: "0 9 * * 1"
   workflow_dispatch: # allows to run manually for testing
-  # pull_request:
-  #   branches:
-  #     - main
-  #   paths:
-  #     - "docs/**"
+  pull_request:
+    branches:
+      - main
+    paths:
+      - "docs/**"
 
 permissions:
   contents: read
@@ -33,6 +33,7 @@ jobs:
           reporter: github-pr-review
           config_file: ".github/.linkspector.yml"
           fail_on_error: "true"
+          filter_mode: "nofilter"
 
       - name: Send Slack notification
         if: failure() && github.event_name == 'schedule'