Fill out the README with details

* Add usage example
* Add details of the inputs

Signed-off-by: Eric Brown <ericwb@users.noreply.github.com>

README.md

@@ -1 +1,41 @@
-# precli-action
+# Precaution Analysis Action
+
+Analyze your source code using Precaution via [precli](https://github.com/securesauce/precli).
+
+## Usage
+
+Here is a minimal complete example to create a Code Scanning action using Precaution.
+
+```yaml
+name: Precaution
+
+on:
+  workflow_dispatch:
+
+jobs:
+  analyze:
+    runs-on: ubuntu-latest
+    permissions:
+      # required for all workflows
+      security-events: write
+      # only required for workflows in private repositories
+      actions: read
+      contents: read
+    steps:
+      - name: Perform Precaution Analysis
+        uses: securesauce/precli-action@v1
+```
+
+## Inputs
+
+### `path`
+
+**Optional** The source file(s) or directory(s) to be analyzed
+
+**Default** `"."`
+
+### `disable`
+
+**Optional** A comma-separated list of rule IDs or names to disable
+
+**Default** `"DEFAULT"`