[antonysastre]

Summary

Hard cutover of she's sheet format from command > description / // to a small markdown-flavored grammar:

• Section headers — any line whose first non-whitespace character is uppercase A–Z (rendered bold cyan).
• Comments — lines starting with # (free-standing; rendered dim italic).
• Commands with optional descriptions — text up to the first # is the command; anything after is the description (rendered green + · + italic). The first # always wins, so URL fragments end the command.
• Blank source lines are now preserved as visual separators between groups instead of being filtered out.

The pager precomputes the longest command in the sheet via a new MaxCommandWidth helper and column-aligns all descriptions; commands sit flush-left (no leading indent). The bespoke ValidateFormat warning block is gone — every line is structurally valid under the new grammar.

Three commits, each compiling and passing tests on its own:

1. feat(sheet): switch to markdown-flavored sheet format
2. feat(sheet): honor blank source lines in View
3. feat(sheet): align descriptions and drop command indent

Existing user sheets in the old format render as plain command lines until ported by hand (no in-tree migration; the user's own sheets were ported separately).