server/README.md: Clarify Docker build context

Previously, narrowing the Docker build context of `server/Dockerfile` to
`/server` was discussed to reduce scope. However, this would exclude
`/sdk`, which is needed for building the server. Locally, it would then
be necessary to explicitly reference `/sdk` as a second build context.
Externally, when using the link to this GitHub repository as build
context, it would lead to unnecessary cloning. As Docker does not yet
support sparse checkouts, referencing subdirectories such as `/server`
results in the entire repository being cloned regardless. Therefore, the
required `/sdk` would be cloned but made unavailable by narrowing the
build context. Any second clone of `/sdk` would therefore result in data
that had already been downloaded being downloaded again. To include
`/sdk` efficiently, the build context must remain the repository root.

This documents the decision of keeping the repository root as the build
context of `server/Dockerfile`. A corresponding note was added in
`server/README.md`.

Additionally, a mention of faulty line endings being a common error when
building the Docker container has been added in `server/README.md`.

Fixes #386

Author: moritzsommer

server/README.md

@@ -18,6 +18,8 @@ The container image can be built via:
 $ docker build -t basyx-python-server -f Dockerfile ..
 ```
 
+Note that when cloning this repository on Windows, Git may convert the line separators to CRLF. This breaks `entrypoint.sh` and `stop-supervisor.sh`. Ensure both files use LF line separators before building. 
+
 ## Running
 
 ### Storage
@@ -77,12 +79,13 @@ services:
     - "8080:80"
     volumes:
       - ./storage:/storage
-
 ````
 
 Here files are read from `/storage` and the server can be accessed at http://localhost:8080/api/v3.0/ from your host system. 
 To get a different setup this compose.yaml file can be adapted and expanded.
 
+Note that the `Dockerfile` has to be specified explicitly, as the build context must be set to the parent directory of `/server` to allow access to the local `/sdk`.
+
 ## Acknowledgments
 
 This Dockerfile is inspired by the [tiangolo/uwsgi-nginx-docker][10] repository.