docs(ctb): Add network-specific to style guide

packages/contracts-bedrock/STYLE_GUIDE.md

@@ -21,9 +21,10 @@ with additional rules. These are:
 We also have the following custom tags:
 
 - `@custom:proxied`: Add to a contract whenever it's meant to live behind a proxy.
-- `@custom:upgradeable`: Add to a contract whenever it's meant to be used in an upgradeable contract.
-- `@custom:semver`: Add to a constructor to indicate the version of a contract.
+- `@custom:upgradeable`: Add to a contract whenever it's meant to be inherited by an upgradeable contract.
+- `@custom:semver`: Add to `version` variable which indicate the contracts semver.
 - `@custom:legacy`: Add to an event or function when it only exists for legacy support.
+- `@custom:network-specific`: Add to state variables which vary between OP Chains.
 
 #### Errors