adding env markdown (#20)

.env.markdown

@@ -0,0 +1,10 @@
+# Environment file info
+
+If you're running in production, you should set these securely.
+
+## file2txt settings
+
+* `GOOGLE_VISION_API_KEY`: YOUR_API_KEY
+	* [Instructions to create an API key are here](https://github.com/muchdogesec/file2txt?tab=readme-ov-file#optional-add-googles-cloud-vision-api-key)
+* `MARKER_API_KEY`: YOUR_API_KEY
+	* [Instructions to create an API key are here](https://github.com/muchdogesec/file2txt?tab=readme-ov-file#optional-add-marker-api-key)

README.md

@@ -37,7 +37,7 @@ source file2txt-venv/bin/activate
 pip3 install -r requirements.txt
 ```
 
-### Set Configuration options
+### Configuration options
 
 file2txt has various settings that are defined in an `.env` file.
 
@@ -47,6 +47,9 @@ To create a template for the file:
 cp .env.example .env
 ```
 
+To see more information about how to set the variables, and what they do, read the `.env.markdown` file.
+
+
 ### Optional: Add Marker API Key (`MARKER_API_KEY`)
 
 file2txt uses the [Marker API](https://www.datalab.to/marker) to process the following filetypes;