Update docs help messages

Author: lcawl

docs/contribute/changelog.md

@@ -26,11 +26,11 @@ Add a new changelog fragment from command-line input
 
 Options:
   --products <List<ProductInfo>>    Required: Products affected in format "product target lifecycle, ..." (e.g., "elasticsearch 9.2.0 ga, cloud-serverless 2025-08-05") [Required]
-  --title <string?>                 Optional: A short, user-facing title (max 80 characters). Required if --pr is not specified. If --pr is specified, will be derived from PR title if not provided. [Default: null]
-  --type <string?>                  Optional: Type of change (feature, enhancement, bug-fix, breaking-change, etc.). Required if --pr is not specified. If --pr is specified, will be derived from PR labels if not provided. [Default: null]
+  --title <string?>                 Optional: A short, user-facing title (max 80 characters). Required if --pr is not specified. If --pr and --title are specified, the latter value is used instead of what exists in the PR. [Default: null]
+  --type <string?>                  Optional: Type of change (feature, enhancement, bug-fix, breaking-change, etc.). Required if --pr is not specified. If mappings are configured, type can be derived from the PR. [Default: null]
   --subtype <string?>               Optional: Subtype for breaking changes (api, behavioral, configuration, etc.) [Default: null]
   --areas <string[]?>               Optional: Area(s) affected (comma-separated or specify multiple times) [Default: null]
-  --pr <string?>                    Optional: Pull request URL or PR number (if --owner and --repo are provided). If specified, --title and --type can be derived from the PR. [Default: null]
+  --pr <string?>                    Optional: Pull request URL or PR number (if --owner and --repo are provided). If specified, --title can be derived from the PR. If mappings are configured, --areas and --type can also be derived from the PR. [Default: null]
   --owner <string?>                 Optional: GitHub repository owner (used when --pr is just a number) [Default: null]
   --repo <string?>                  Optional: GitHub repository name (used when --pr is just a number) [Default: null]
   --issues <string[]?>              Optional: Issue URL(s) (comma-separated or specify multiple times) [Default: null]