chore: ignore local build artifacts and backups

Author: dhanush varma

.gitignore

@@ -155,3 +155,19 @@ windows/*/debug/*
 windows/*/CACHEDIR.TAG
 windows/.rustc_info.json
 linux/configure~
+
+# local junk
+build-system/
+*.backup
+*.save
+*.patch
+*.a
+README.srt
+no_subs.ts
+
+fix_hardsubx.cmake
+fix_libraries.cmake
+mac/configure~
+*.current
+
+