Update brusselator.md with Multiple Shooting

[sharvmurgai]

Changed the current version of Brusselator.md to use multiple shooting techniques to improve the performance.

[ChrisRackauckas-Claude]

The CI is failing because this branch was created before PR #1316 which switched the codebase from JuliaFormatter to Runic.jl for formatting. As a result, the format check is failing due to the branch being based on an older version of master.

Solution: The branch needs to be rebased on the latest master. This will incorporate the Runic formatting changes and only leave the brusselator.md documentation changes.

To fix this, run:

git fetch origin master
git rebase origin/master
git push --force-with-lease origin brusselator

Alternatively, I can create a new PR with these changes if that's easier.

The DiffEqFlux "Multiple Shooting" test error (worker died with SIGSEGV) appears to be a flaky test issue in the downstream testing and is likely unrelated to these documentation changes.

cc @ChrisRackauckas

🤖 Generated with Claude Code