Documentation improvements

[delucchi-cmu]

• 'overwrite' param has been removed
• expand contact information; include calendar widget
• similar updates to contribution guide from Spruce up the contribution guide. lsdb#531
• use new aggregate_column_statistics for index division estimation

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.55%. Comparing base (f99ef80) to head (60aa1e5).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #462   +/-   ##
=======================================
  Coverage   94.55%   94.55%           
=======================================
  Files          28       28           
  Lines        1615     1615           
=======================================
  Hits         1527     1527           
  Misses         88       88           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.