Build the server locally about souffle-lsp-plugin

[XiaowenHu96]

Thanks for the clear instruction, I'll give it a try and get back to you next week.

[jdaridis]

There is no need to build the server yourself. The process is already complete, but I had the resulting jar under .gitignore, oops. Now it is visible.

To integrate the server with a client you need to set up a script running .jar file as I do for the VS code extension in https://github.com/jdaridis/souffle-lsp-plugin/blob/master/src/main/vs-code/extension.ts line 74-79.
For Vim I imagine there is a similar process, you have to write a script for vim to know when it detects a .dl file to run the .jar file. From a quick Google search, I see that the Vim team has good documentation on how to implement the client side

[jdaridis]

I added the jar file as a release to make it easier to find.

Also for completeness, to build the java source code run ./gradlew jar on the top level.
I updated the README file with more instructions on how to build and run the standalone server.