gitignore: add symlinked devnet and mainnet circuits directories

Author: dannywillems

.gitignore

@@ -13,4 +13,9 @@ cargo-build-test.json
 tests.tsv
 
 # Generated API docs should not be committed
-website/static/api-docs/
+website/static/api-docs/
+
+ledger/3.0.0devnet
+ledger/3.0.0mainnet
+ledger/3.0.1devnet
+ledger/berkeley_rc1