Add support for 'defaultBranch' parameter (#55)

Adding support for
[`defaultBranch`](https://github.com/launchdarkly/ld-find-code-refs/blob/main/docs/CONFIGURATION.md?plain=1#L46)
for GitHub Action.

Author: jrcryer-aviva

README.md

@@ -99,4 +99,5 @@ If the action fails, there may be a problem with your configuration. To investig
 | `repoName` | <p>The repository name. Defaults to the current GitHub repository.</p> | `false` | `""` |
 | `prune` | <p>There is a known issue where the GitHub Action will not prune deleted branch data in private repos. Only enable this if you are running the action in a public repo.</p> | `false` | `false` |
 | `subdirectory` | <p>The subdirectory to run the action in.</p> | `false` | `""` |
+| `defaultBranch` | <p>The default branch. The LaunchDarkly UI will default to this branch. If not provided, will fallback to 'main'.</p> | `false` | `""` |
 <!-- action-docs-inputs source="action.yml" -->

action.yml

@@ -45,6 +45,9 @@ inputs:
   subdirectory:
     description: "The subdirectory to run the action in."
     required: false
+  defaultBranch:
+    description: "The default branch. The LaunchDarkly UI will default to this branch. If not provided, will fallback to 'main'."
+    required: false
 runs:
   using: 'docker'
   image: 'Dockerfile'
@@ -60,3 +63,4 @@ runs:
     LD_LOOKBACK: ${{ inputs.lookback }}
     LD_PRUNE: ${{ inputs.prune }}
     LD_SUBDIRECTORY: ${{ inputs.subdirectory }}
+    LD_DEFAULT_BRANCH: ${{ inputs.defaultBranch }}