Document required post-`make setup` git/GitHub actions

[turbomam]

I'm confused by my git status after make setup, or what I should do next to get this "into my GH account"

git status

On branch master
Untracked files:
(use "git add ..." to include in what will be committed)
project/java/

nothing added to commit but untracked files present (use "git add" to track)

but that seems to contradict the git init and git add results from from make setup

Then

git push

fatal: No configured push destination.
Either specify the URL from the command-line or configure a remote repository using

git remote add <name> <url>

and then push using the remote name

git push <name>

Let's add documentation that clarifies how to get this into a new repo hosted on GitHub.

[turbomam]

https://www.digitalocean.com/community/tutorials/how-to-push-an-existing-project-to-github

[turbomam]

What to use for repo name? Name of LinkML YAML file in src/linkml ?

Is this supposed to be reflected in the id, name, title or any other schema annotations? See #10 ?

[turbomam]

Created by going to https://github.com/new, entering desired Repository name, but no other repo settings. I want to see what gets passed on from the git init part of make setup

[turbomam]

Follow GH's push an existing repository from the command line instructions

git remote add origin git@github.com:<USER/ORG>/<REPO NAME>.git
git branch -M main
git push -u origin main

Note this changes the the name of the root branch from the default of master to main. Most people would probably want that nowadays.