Improvements in install script

[zjeffer]

I made some improvements to the install script that made it easier for me to debug problems, so I thought I'd share them.

[zjeffer]

I noticed git pull doesn't always seem to work (when already checked out to a specific commit), specifying origin main fixed that.

[leftas]

While you are at it, when checking out the specific commit, make sure to update the submodules, as well.
Probably this should suffice: git -C "$HYPRLAND_PATH" submodule update --recursive

Current flow - is that if git has updated to the newest wlroots or other submodules, which also has some breaking changes with regard to checked out version, then the script may fail to build hyprland. For example, as of now, we have v0.31 version and current git version which fails to build because wlroots, which are used in git version, made some breaking changes for v0.31 version.

[zjeffer]

Also fixed #27 in latest commit.

[zjeffer]

Closing due to deprecation