Assign RUSTSEC IDs (#325)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]

crates/stb_truetype/RUSTSEC-0000-0000.toml renamed to crates/stb_truetype/RUSTSEC-2020-0020.toml

@@ -1,5 +1,5 @@
 [advisory]
-id = "RUSTSEC-0000-0000"
+id = "RUSTSEC-2020-0020"
 package = "stb_truetype"
 date = "2020-04-18" # date when deprecation was announced on project README
 title = "`stb_truetype` crate has been deprecated; use `ttf-parser` instead"