Update steps for 'Getting the source code' and link 'Git Bootcamp'

[abdnafees]

This PR contains the following changes mentioned in issue number #964:

• list all upstream-related commands in a single step and code block
• have the same commands in the boot camp, but with more in-depth discussions (e.g. why they are necessary)
• from here, link to the boot camp so that people that want more details can find them there
• add a couple of comments about the duplicated commands as a reminder for people updating either page

[ghost]

All commit authors signed the Contributor License Agreement.

[ezio-melotti]

Thanks for the PR!

There are two .DS_Store files that got included accidentally and should be removed.
I usually use git add -p while adding changes, in order to both verify exactly what gets added and to review it while I do (and sometimes also to break changes into multiple commits).

[abdnafees]

Sorry about that let me remove them.

[abdnafees]

Would it be useful to add .DS_Store to .gitignore?

[abdnafees]

I hope it worked, I can't see the files now. Please confirm.

[Mariatta]

We need a newline at the end of the file.

Suggested change

	.ropeproject
	.ropeproject

[abdnafees]

Alright, let me add it.

[abdnafees]

Please check now.

[abdnafees]

Why doesn't it show the new line I added?

[ezio-melotti]

I'm not sure why, but it also doesn't belong to this PR.

I will batch-commit my suggestions and merge this.

[abdnafees]

Got it, thank you for the help.

[ezio-melotti]

Done, thanks for the PR!

[abdnafees]

Thank you for the assistance. Really appreciate it.