Added section & environment folding to the latex parser #493

Job	Run time
test (ubuntu-latest, 27.2, false)	50s
test (ubuntu-latest, 28.2, false)	48s
test (ubuntu-latest, 29.1, false)	46s
test (macos-latest, 27.2, false)	2m 40s
test (macos-latest, 28.2, false)	2m 36s
test (macos-latest, 29.1, false)	2m 52s
test (windows-latest, 27.2, false)	52s
test (windows-latest, 28.2, false)	50s
test (windows-latest, 29.1, false)	53s
test (ubuntu-latest, snapshot, true)	37s
test (macos-latest, snapshot, true)	2m 0s
test (windows-latest, snapshot, true)	38s
	16m 22s

Provide feedback