docs(compartment-mapper): Workspace language-for-extension options

packages/compartment-mapper/NEWS.md

@@ -9,6 +9,12 @@ User-visible changes to `@endo/compartment-mapper`:
   package’s `type` in the way we already vary `js` between `cjs` and `mjs`.
   These options enter through the high level functions including `makeArchive`
   and `importLocation`.
+- The new options `workspaceLanguageForExtension`,
+  `workspaceModuleLanguageForExtension`, and
+  `workspaceCommonjsLanguageForExtension` apply like the above except more
+  specifically and for packages that are not physically located under a
+  `node_modules` directory, indicating that JavaScript has not yet been
+  generated from any non-JavaScript source files.
 - Omits unused module descriptors from `compartment-map.json` in archived
   applications, potentially reducing file sizes.
 - Fixes an issue where errors thrown from exit module hooks (`importHook`) would

packages/compartment-mapper/README.md

@@ -263,6 +263,13 @@ Packages with `type` set to `"commonjs"` or simply not set,
 This provides an hook for mapping TypeScript's `.ts` to either `.cts` or
 `.mts`.
 
+The analogous `workspaceLanguageForExtension`,
+`workspaceCommonjsLanguageForExtension`, and
+`workspaceModuleLanguageForExtension` options apply more specifically for
+packages that are not under a `node_modules` directory, indicating that they
+are in the set of linked workspaces and have not been built or published to
+npm.
+
 In the scope any given package, the `parsers` property in `package.json` may
 override the extension-to-language mapping.