docs: update README with Docker instructions and details

Enhance the README by adding detailed Docker usage instructions, 
including build, version check, and conversion commands for both 
Windows and Linux. This improves accessibility for users who 
prefer using Docker for the project.

README.md

@@ -66,12 +66,39 @@ result = md.convert("example.jpg")
 print(result.text_content)
 ```
 
-### Docker
+<details>
+<summary>Docker</summary>
+
+#### Build
 
 ```sh
 docker build -t markitdown:latest .
-docker run --rm -i markitdown:latest < ~/your-file.pdf > output.md
 ```
+
+#### Check version
+
+```sh
+docker run --rm markitdown:latest --version
+```
+
+#### Convert
+
+- On Windows (PowerShell):
+
+```sh
+docker run --rm --volume ${pwd}:/src --workdir /src markitdown:latest ./path-to-your-file.pdf
+```
+
+- On Linux:
+
+```sh
+docker run --rm --volume $(pwd):/src --workdir /src markitdown:latest ./path-to-your-file.pdf
+```
+
+Note: When specifying the file path, always use `/` as the separator, even on Windows (e.g., ./my-folder/my-file.pdf).
+
+</details>
+
 <details>
 
 <summary>Batch Processing Multiple Files</summary>