fix: Add DS_Store in the gitignore list (#638)

**What problem does this PR solve?**:
Updating the .gitignore file to exclude .DS_Store file

**Which issue(s) this PR fixes**:
Fixes # <No fix number>

**How Has This Been Tested?**:
This is a trivial change. This does not affect the build / product in
anyways. Manually tested to see that git was ignoring .DS_Store file on
OSX.

Author: prajnutanix

.gitignore

@@ -1,5 +1,8 @@
 .vscode/
 
+# ignore metadata files generated by OSX operating system
+.DS_Store
+
 test-output/
 dist