fix: add WithHardTabs/WithBackspace options and fix doc bugs

[GautamKumarOffical]

Summary

This PR addresses issue #1635 and fixes several documentation bugs.

New WithHardTabs and WithBackspace options

The v2 cursor optimization in cursedRenderer auto-detects the terminal's TAB0 flag via termios and replaces runs of space cells with \t characters as a cursor-movement optimization. This silently corrupts application output that relies on precise space-based column alignment (see #1635).

Previously there was no way to disable this behavior. This PR adds:

• tea.WithHardTabs(bool) — explicitly enable or disable hard tab optimization
• tea.WithBackspace(bool) — explicitly enable or disable backspace optimization

When these options are not set, the auto-detection from termios continues to work as before. When they are set, the explicit value takes precedence.

Usage:

p := tea.NewProgram(model{}, tea.WithHardTabs(false))

Documentation fixes

• InterruptMsg doc incorrectly said "signals the program should suspend" — changed to "interrupt"
• ResumeMsg doc had a grammar error ("listen" → "listened")
• BackgroundColorMsg example was missing return m, nil and referenced [Update.Init] instead of [Model.Init]
• KeyboardEnhancements doc example used non-existent msg.ReportEventTypes field instead of msg.SupportsEventTypes() method
• Removed duplicate KeyboardEnhancements doc comment

Testing

All existing tests pass. The changes are backward-compatible — no existing behavior changes unless WithHardTabs/WithBackspace are explicitly set.

[GautamKumarOffical]

Hi! This PR adds WithHardTabs/WithBackspace options and fixes several doc bugs. All checks pass. Happy to make any adjustments. Thanks!

[codecov]

Codecov Report

❌ Patch coverage is 0% with 10 lines in your changes missing coverage. Please review.
✅ Project coverage is 55.92%. Comparing base (a23da80) to head (95d4ccf).

Files with missing lines	Patch %	Lines
options.go	0.00%	6 Missing ⚠️
tea.go	0.00%	2 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1722      +/-   ##
==========================================
- Coverage   56.50%   55.92%   -0.58%     
==========================================
  Files          25       25              
  Lines        1315     1325      +10     
==========================================
- Hits          743      741       -2     
- Misses        482      491       +9     
- Partials       90       93       +3     

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[GautamKumarOffical]

Fixed a typo in the WithBackspace test — was checking hardTabsOverride instead of backspaceOverride. All tests pass now. The codecov report was from an earlier commit before the tests were added.