doc/languages-frameworks/javascript: add npmWorkspace and npmPruneFlags args

* `npmDepsHash`: The output hash of the dependencies for this project. Can be calculated in advance with [`prefetch-npm-deps`](#javascript-buildNpmPackage-prefetch-npm-deps).

* `makeCacheWritable`: Whether to make the cache writable prior to installing dependencies. Don't set this unless npm tries to write to the cache directory, as it can slow down the build.

* `npmBuildScript`: The script to run to build the project. Defaults to `"build"`.

* `npmWorkspace`: The workspace directory within the project to build and install.

* `dontNpmBuild`: Option to disable running the build script. Set to `true` if the package does not have a build script. Defaults to `false`. Alternatively, setting `buildPhase` explicitly also disables this.

* `dontNpmInstall`: Option to disable running `npm install`. Defaults to `false`. Alternatively, setting `installPhase` explicitly also disables this.

* `npmFlags`: Flags to pass to all npm commands.

* `npmInstallFlags`: Flags to pass to `npm ci` and `npm prune`.

* `npmInstallFlags`: Flags to pass to `npm ci`.

* `npmBuildFlags`: Flags to pass to `npm run ${npmBuildScript}`.

* `npmPackFlags`: Flags to pass to `npm pack`.

* `npmPruneFlags`: Flags to pass to `npm prune`. Defaults to the value of `npmInstallFlags`.

#### prefetch-npm-deps {#javascript-buildNpmPackage-prefetch-npm-deps}