docs: drop stale PATH reference from getBinPath header

Per CodeRabbit's review of the revert commit: the module-level
comment still listed "or on the system PATH" as a resolution source,
but the PATH probe was removed two commits back. Updated to match
the actual behavior (probe paths under vscode.env.appRoot only).

Author: 0xMink

src/services/ripgrep/index.ts

@@ -11,7 +11,7 @@ This file provides functionality to perform regex searches on files using ripgre
 Inspired by: https://github.com/DiscreteTom/vscode-ripgrep-utils
 
 Key components:
-1. getBinPath: Locates the ripgrep binary (in the VS Code install, or on the system PATH).
+1. getBinPath: Locates the ripgrep binary inside the VS Code installation.
 2. execRipgrep: Executes the ripgrep command and returns the output.
 3. regexSearchFiles: The main function that performs regex searches on files.
    - Parameters: