todo.sr.ht: fix typo

todo.sr.ht: document new comment editing API

todo.sr.ht: document the new ~u/n{,/0}/{,un}subscribe addresses

todo.sr.ht: narrow down who can submit what over e-mail

all: fix broken relative links

todo.sr.ht: fix broken links throughout document

Fixes https://todo.sr.ht/~sircmpwn/todo.sr.ht/212

Signed-off-by: Sam Whited <sam@samwhited.com>

Overhaul installation documentation

Add an install manual for dispatch.sr.ht and dummy ones for man & todo

Fix underscores on todo.sr.ht/api.md

Add todo.sr.ht API docs

Clarify anonymous todo email submissions

Email todo submissions are currently only accepted from logged-in users (see
~sircmpwn/todo.sr.ht#170). This provides temporary clarification to prevent
confusion.

Add docs for use of email with todo.sr.ht

Add YAMl frontmatter to all pages

Add more todo.sr.ht search filters

Specifically the recently introduced no-filters and ticket assignment.

Add documentation for user/ticket mentions

Write todo.sr.ht docs

Add todo.sr.ht placeholder