chore(diagnostics): changelog and description

Author: NathanSnail

changelog.md

@@ -1,6 +1,7 @@
 # changelog
 
 ## Unreleased
+* `NEW` diagnostic: `no-unknown-operations`
 <!-- Add all new changes here. They will be moved under a version at release -->
 
 ## 3.16.0

locale/en-us/setting.lua

@@ -425,6 +425,8 @@ config.diagnostics['unnecessary-assert']    =
 'Enable diagnostics for redundant assertions on truthy values.'
 config.diagnostics['no-unknown']            =
 'Enable diagnostics for cases in which the type cannot be inferred.'
+config.diagnostics['no-unknown-operations']            =
+'Enable diagnostics for cases in which the result type of an operation cannot be inferred.'
 config.diagnostics['not-yieldable']         =
 'Enable diagnostics for calls to `coroutine.yield()` when it is not permitted.'
 config.diagnostics['param-type-mismatch']   =