docs: update scoop installation note

[aliesbelik]

• Update scoop installation note. Since available and regularly updated in scoop's main bucket (originally added as ScoopInstaller/Main#422), lab can be installed without adding additional buckets.

• Minor formatting enhancements across README.

[codecov[bot]]

Codecov Report

All modified lines are covered by tests :white_check_mark:

Comparison is base (644d19a) 55.70% compared to head (4b2a56c) 55.70%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #883 +/- ## ======================================= Coverage 55.70% 55.70% ======================================= Files 82 82 Lines 5953 5953 ======================================= Hits 3316 3316 Misses 2349 2349 Partials 288 288 ```

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[prarit]

Sorry for the late review. Approved.