Update figwheel instructions

[zzantares]

I was trying to follow the documentation but it did not work. This is to match
what figwheel-main-template produces, it could trip up new ClojureScript
users.

When using -A I got a warning about it being deprecated in favour of -M,
I'm hacking in a local project and following the updated instructions works.

---

Before submitting the PR make sure the following things have been done (and denote this
by checking the relevant checkboxes):

• The commits are consistent with our contribution guidelines
• You've added tests (if possible) to cover your change(s)
• All tests are passing (eldev test)
• All code passes the linter (eldev lint) which is based on elisp-lint and includes
  • byte-compilation, checkdoc, check-declare, packaging metadata, indentation, and trailing whitespace checks.
• You've updated the changelog (if adding/changing user-visible functionality)
• You've updated the user manual (if adding/changing user-visible functionality)

Thanks!

If you're just starting out to hack on CIDER you might find this section of its
manual extremely useful.

[vemv]

Nice - thanks much for your contribution!

[vemv]

let's name the alias fig-build

[zzantares]

well this is exactly what prompted me to submit the PR, that the alias name (and the shape of the map) did not matched this https://github.com/bhauman/figwheel-main-template#compiling-the-generated-project

And it is already hinted in CIDER docs:

These should already be present if you used the figwheel-main-template with clj-new to generate your deps.edn

but the alias shown is not the one already present in the template.

Sorry for the confusion!

[bbatsov]

Got it.