update the bot messages related to bootstrap changes

Signed-off-by: onur-ozkan <[email protected]>

Author: onur-ozkan

triagebot.toml

@@ -583,11 +583,11 @@ message = "Third-party dependency whitelist may have been modified! You must ens
 cc = ["@davidtwco", "@wesleywiser"]
 
 [mentions."src/bootstrap/src/core/config"]
-message = "This PR modifies `src/bootstrap/src/core/config`. If appropriate, please also update `CONFIG_CHANGE_HISTORY` in `src/bootstrap/src/lib.rs` and `change-id` in `config.example.toml`."
+message = "This PR modifies `src/bootstrap/src/core/config`. If appropriate, explain what rustc devs should change in their config.toml within the PR description, update `CONFIG_CHANGE_HISTORY` in `src/bootstrap/src/lib.rs` and `change-id` in `config.example.toml`."
 [mentions."src/bootstrap/defaults"]
-message = "This PR modifies `src/bootstrap/defaults`. If appropriate, please also update `CONFIG_CHANGE_HISTORY` in `src/bootstrap/src/lib.rs` and `change-id` in `config.example.toml`."
+message = "This PR modifies `src/bootstrap/defaults`. If appropriate, explain what rustc devs should change in their config.toml within the PR description, update `CONFIG_CHANGE_HISTORY` in `src/bootstrap/src/lib.rs` and `change-id` in `config.example.toml`."
 [mentions."config.example.toml"]
-message = "This PR changes `config.example.toml`. If appropriate, please also update `CONFIG_CHANGE_HISTORY` in `src/bootstrap/src/lib.rs` and `change-id` in `config.example.toml`."
+message = "This PR changes `config.example.toml`. If appropriate, explain what rustc devs should change in their config.toml within the PR description, update `CONFIG_CHANGE_HISTORY` in `src/bootstrap/src/lib.rs` and `change-id` in `config.example.toml`."
 
 [mentions."src/bootstrap/defaults/config.compiler.toml"]
 message = "This PR changes src/bootstrap/defaults/config.compiler.toml. If appropriate, please also update `config.codegen.toml` so the defaults are in sync."