Add extra-input-files for deeper file nesting if needed

.github/workflows/check-links.yml

@@ -25,6 +25,10 @@ on:
         description: Message to display in job summary
         required: false
         type: string
+      extra-input-files:
+        description: Additional files to scan for links beyond default *.md and **/*.md
+        required: false
+        type: string
       override-args:
         description: Override default arguments (see https://github.com/lycheeverse/lychee#commandline-parameters)
         required: false
@@ -51,7 +55,8 @@ jobs:
           # args: --base . --verbose --no-progress -a '200,403,429,500' './**/*.md' 
           # args: --config ./.github/workflows/lychee.toml './**/*.md'
           # Need to use ./*.md _and_ ./**/.md because runner shell glob processing does not include current dir
-          args: ${{ inputs.exclude }} --verbose --no-progress -a '200,403,429,500' --base . ./*.md ./*/*.md
+          # If there are files more than one directory below ., then need to add as extra-input-files
+          args: ${{ inputs.exclude }} --verbose --no-progress -a '200,403,429,500' --base . ./*.md ./*/*.md ${{ inputs.extra-input-files }}
           fail: true
       - name: Link Checker user-supplied args
         if: ${{ inputs.override-args }}