Split follow ups

[tony]

Follow up to #532

Changes

Split fixes

• Keyword-only style arguments
• Fix passing through target

New window fixes

• Fix window_index

[codecov]

Codecov Report

Attention: Patch coverage is 25.00000% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 88.66%. Comparing base (fe27280) to head (271f7b9).

Files	Patch %	Lines
src/libtmux/pane.py	0.00%	1 Missing and 1 partial ⚠️
src/libtmux/session.py	50.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #534      +/-   ##
==========================================
- Coverage   88.72%   88.66%   -0.07%     
==========================================
  Files          37       37              
  Lines        3965     3969       +4     
  Branches      573      575       +2     
==========================================
+ Hits         3518     3519       +1     
- Misses        307      308       +1     
- Partials      140      142       +2     

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