Merge submodules

[DaltonSW]

Commands run to produce this:

# Remove submodule
git rm -rf include/lib/BrawlHeaders .git/modules .gitmodules
git commit -am "Remove submodule"

# Add first subtree
git subtree add include/lib/BrawlHeaders https://github.com/Sammi-Husky/BrawlHeaders main

# Second subtree
git rm -rf include/lib/BrawlHeaders/OpenRVL
git commit -am "Remove empty dir"
git subtree add include/lib/BrawlHeaders/OpenRVL https://github.com/Sammi-Husky/open_rvl main

I ran these without --squash so the commit history and attribution would stay accurate.

Commits to those directories can now be made as part of this repo without the need for getting stuff merged into submodules first. To sync them back to the root repos, anybody with push access to the original repos can run:

# If your git(hub) is configured to use SSH for auth, you should swap 
# the URLs below for the SSH-compatible ones 

# BrawlHeaders
git subtree push --prefix include/lib/BrawlHeaders https://github.com/Sammi-Husky/BrawlHeaders

# OpenRVL
git subtree push --prefix include/lib/BrawlHeaders/OpenRVL https://github.com/Sammi-Husky/open_rvl

I'm admittedly unsure of what will happen if OpenRVL is cloned and someone tries pushing to BrawlHeaders. That directory still contains a .gitmodules file, so git might just choose to ignore everything inside of it since it's marked a submodule

[decomp-dev]

Report for RSBE01_02 (b96b501 - ec07d20)

No changes

[mparisi20]

I think the commits should be squashed, given that BrawlHeaders is not going away under our broader plan. All this history will be preserved in the original repo; we will just stop accepting direct edits to it and ask people to (re-)open their PRs here now. I'd like to avoid duping a ton of history and burying commits we've made here so far.

[DaltonSW]

Updated to squash. I did some research and it seems like with subtrees, this should let us still push new commits onto the base repo without requiring force-pushing the squash as well, which I was initially concerned about. I didn't want to rewrite the history of the submodules