docs: clean up

[lennartkloock]

• Removes headlines from crate root docs

Otherwise it would look like this when rendered:

CLOUD-35

[cloudflare-workers-and-pages]

Deploying scuffle-docrs with    Cloudflare Pages

Latest commit:	7015c75
Status:	✅  Deploy successful!
Preview URL:	https://d7b560da.scuffle-docrs.pages.dev
Branch Preview URL:	https://pr-259.scuffle-docrs.pages.dev

View logs

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 63.05%. Comparing base (fa14d64) to head (7015c75).
Report is 24 commits behind head on main.

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #259      +/-   ##
==========================================
+ Coverage   63.00%   63.05%   +0.05%     
==========================================
  Files         202      202              
  Lines       15849    15849              
==========================================
+ Hits         9985     9994       +9     
+ Misses       5864     5855       -9     

Files with missing lines	Coverage Δ
crates/aac/src/lib.rs	89.65% <ø> (ø)
crates/bootstrap/src/lib.rs	0.00% <ø> (ø)
crates/bootstrap/telemetry/src/lib.rs	76.78% <ø> (ø)
crates/context/src/lib.rs	100.00% <ø> (ø)
crates/expgolomb/src/lib.rs	100.00% <ø> (ø)
crates/metrics/derive/src/lib.rs	80.00% <ø> (ø)
crates/signal/src/lib.rs	100.00% <ø> (ø)

... and 1 file with indirect coverage changes

Components	Coverage Δ
scuffle-batching	100.00% <ø> (ø)
scuffle-bootstrap	88.02% <ø> (+1.51%)	⬆️
scuffle-context	100.00% <ø> (ø)
scuffle-ffmpeg	31.81% <ø> (ø)
scuffle-h3-webtransport	0.00% <ø> (ø)
scuffle-http	22.48% <ø> (ø)
scuffle-metrics	66.39% <ø> (ø)
scuffle-pprof	100.00% <ø> (ø)
scuffle-settings	0.00% <ø> (ø)
scuffle-signal	100.00% <ø> (ø)
postcompile	76.87% <ø> (ø)
scuffle-image-processor	∅ <ø> (∅)

[TroyKomodo]

?brawl merge

[scuffle-brawl]

📌 Commit 7015c75 has been approved and added to the merge queue.

Requested by: @TroyKomodo

Approved by: @TroyKomodo

[scuffle-brawl]

⌛ Trying commit 7015c75 with merge ba5e35e...

[scuffle-brawl]

🎉 Build successful!
Completed in 1:54

• brawl-done

Approved by: @TroyKomodo
Pushing ba5e35e to main