Add comment to explain how tmp rust advisories are handled

Signed-off-by: Shivam Sandbhor <shivam.sandbhor@gmail.com>

Author: sbs2001

vulnerabilities/importers/rust.py

@@ -67,6 +67,8 @@ def updated_advisories(self) -> Set[Advisory]:
         return self._load_advisories(self._updated_files)
 
     def _load_advisories(self, files) -> Set[Advisory]:
+        # per @tarcieri It will always be named RUSTSEC-0000-0000.md
+        # https://github.com/nexB/vulnerablecode/pull/281/files#r528899864
         files = [f for f in files if not f.endswith("-0000.md")]  # skip temporary files
         packages = self.collect_packages(files)
         self.set_api(packages)