Expand docs with default install behavior as of v2, non-default requirements.txt file paths. and toggle configs

Author: chrissimpkins

README.md

@@ -28,24 +28,28 @@ None
 
 ### Default
 
-Uses path `requirements.txt` and updates `pip` before the install.
+Uses path `requirements.txt` and updates `pip`, `setuptools`, and `wheel` before the install.
 
 ```yaml
 - name: Install Python dependencies
   uses: py-actions/py-dependency-install@v2
 ```
 
-### Disable `pip` update before install
+### Define the `requirements.txt` path
+
+Define a requirements.txt file on a path relative to the root of your repository.
 
 ```yaml
 - name: Install Python dependencies
   uses: py-actions/py-dependency-install@v2
   with:
-    update-pip: "false"
+    path: "path/to/requirements.txt"
 ```
 
 ### Toggle `pip`, `setuptools`, and `wheel` installs/updates off
 
+The `pip`, `setuptools`, and `wheel` install/updates can be toggled off in your configuration. Use one or more of the `update-pip`, `update-setuptools`, and `update-wheel` settings with a boolean string to customize the default behavior:
+
 ```yaml
 - name: Install Python dependencies
   uses: py-actions/py-dependency-install@v2