Fix build script location output

[pushfoo]

Changes

• make.py tells you where the output files are relative to the build script, like it used to
• Home directory templating is restored in a few edge cases

Also ty to @tiffanyxiao for some really nice PR formatting (#1721, #1723)! I may adopt aspects of it going forward.

How to test

1. cd into the project root
2. Run python make.py html
3. Observe the following output:

   Running Sphinx v6.1.3
   ...[ removed for brevity ]...
   build succeeded.
   
   The HTML pages are in build/html.
   
   Build finished. The HTML pages are in doc/build/html.

Why

tl;dr less confusing to beginners

The behavior on development is currently not user friendly as it literally copies the Makefile syntax:

$ python make.py html
Running Sphinx v6.1.3
 ...[ removed for brevity ]...
build succeeded.

The HTML pages are in build/html.

Build finished. The HTML pages are in $(BUILDDIR)/html.

Since we have a 1:1 port of the Makefile, we may as well go the full mile in restoring home directory templating too. It might be useful to have in git history as boilerplate for someone later.