Add documentation for the new feature

README.md

@@ -20,15 +20,13 @@ This will create an image from the [`Dockerfile`](Dockerfile) and tag it as `xle
 
 To parse a sentence using xle-docker, you need two things:
 
-* The path to an LFG grammar file, e.g. `/home/mustermann/grammatik.lfg`
+* A grammar, e.g. stored in the file `/home/mustermann/grammatik.lfg`
 * A sentence, e.g. `in der Arena veranstalten die Ritter ein Turnier .`
 
-Then, you have to execute the following command:
+You can then execute the following command:
 
 ```bash
-sudo docker run -it \
-     --mount type=bind,source=/home/mustermann/grammatik.lfg,target=/grammar.lfg \
-     xle "in der Arena veranstalten die Ritter ein Turnier ."
+sudo docker run -i xle "in der Arena veranstalten die Ritter ein Turnier ." < /home/mustermann/grammatik.lfg
 ```
 
 This will take a few seconds. The parses will then be output to the command line using XLE's own XML export format. If you want to store the output in a file, append `> name_of_your_file.xml` at the end of the command.
@@ -39,6 +37,18 @@ This will take a few seconds. The parses will then be output to the command line
 Note that the `xle` specified in the `docker run` command is the name of the tag you've given the image when building, _not_ the command to be executed (although under the hood the container will call a Linux command also called `xle`).
 </details>
 
+<details>
+<summary>Alternative using mounts</summary>
+
+The container also allows the Grammar file to be mounted as `/grammar.lfg`, if this is more useful for your specific use case:
+
+```bash
+sudo docker run \
+     --mount type=bind,source=/home/mustermann/grammatik.lfg,target=/grammar.lfg \
+     xle "in der Arena veranstalten die Ritter ein Turnier ."
+```
+</details>
+
 ## :page_with_curl: About
 
 Here, a more detailed explanation of the relevant files is given. The used sources are marked with :books:.