docs: Use 'develop' extra over removed 'complete' (#2113)

* Update all uses of the removed 'complete' extra to 'develop'.
   - The 'complete' extra was removed when moving to hatchling in
     PR #2095, but the 'develop' extra retains most of that functionality.
   - Update the 'complete' extra to 'all' for the Binder postBuild to
     reduce the number of dependencies that need to be installed.
* Quote the extra for best practice to ensure compatibility across shells.

Author: matthewfeickert

CONTRIBUTING.md

@@ -55,7 +55,7 @@ We recommend first reading the "[Developing](https://scikit-hep.org/pyhf/develop
 You can install the development environment (which includes a number of extra) libraries and all others needed to run the tests via `pip`:
 
 ```console
-python -m pip install --upgrade --editable .[complete]
+python -m pip install --upgrade --editable '.[develop]'
 ```
 
 To make the PR process much smoother we also strongly recommend that you setup the Git pre-commit hook for [Black](https://github.com/psf/black) by running

binder/postBuild

@@ -1,2 +1,2 @@
-python -m pip install --upgrade .[complete]
+python -m pip install --upgrade '.[all]'
 python -m pip install altair

docs/development.rst

@@ -20,7 +20,7 @@ and install all necessary packages for development
 
 .. code-block:: console
 
-    python -m pip install --upgrade --editable '.[complete]'
+    python -m pip install --upgrade --editable '.[develop]'
 
 Then setup the Git `pre-commit <https://pre-commit.com/>`__ hooks by running