Update installation guidance and silence typechecking

[asullivan-blze]

Relates to PR #61.

What and why?

While I'd like to eventually get this into Poetry to allow for isolated development, at least isolating this via pipx so it doesn't lead to dependency chaos for system/user packages should be what we recommend. (And it's how I have my copy of ansible and boardwalk installed locally.)

Additionally, resolves the issue from some change in Pyright now triggering a failure over in PR #61.

/home/runner/work/boardwalk/boardwalk/src/boardwalk/manifest.py
  /home/runner/work/boardwalk/boardwalk/src/boardwalk/manifest.py:139:17 - error: Expression of type "tuple[tuple[str]]" cannot be assigned to declared type "tuple[str]"
    "tuple[str]" is incompatible with "str" (reportAssignmentType)
1 error, 0 warnings, 0 informations 
make: *** [Makefile:83: test-pyright] Error 1
Error: Process completed with exit code 2.

How was this tested?

make test; no errors.

[metadaddy]

All looks good to me, especially the blank lines before function definitions. Gotta love linting tools! ;-)