Update docs

website/src/pages/docs/handlers/openapi.mdx

@@ -52,7 +52,7 @@ We use `operationId` for the names, and aim to keep it as close as possible to o
 ### Type naming
 
 We adjust `operationId` only when necessary according to the GraphQL spec:
-    - Chars  ` ` (white space), `.`, `/` and `-` are replaced with `_` (underscore)
+    - Chars  ` ` (white space), `.`, `/`, `:` and `-` are replaced with `_` (underscore)
     - Other chars which are not latin/digits are replaced with their char codes
     - If first char of the name is a digit, we prefix it with `_` (GraphQL spec doesn’t allow that)