Update installation docs for prerelease

[t1m0thyj]

See the updated docs here: https://zowe-client-python-sdk--254.org.readthedocs.build/en/254/usage/installation.html

Also updates the PyEnchant dev dep to support M1 Macs so that I could build the docs from source 😋

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 83.83%. Comparing base (3cf2cd0) to head (d1dc85e).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #254   +/-   ##
=======================================
  Coverage   83.83%   83.83%           
=======================================
  Files          34       34           
  Lines        2116     2116           
=======================================
  Hits         1774     1774           
  Misses        342      342           

Flag	Coverage Δ
unittests	83.83% <ø> (ø)

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