Caret operator in documentation (jupyterlab#13856)

* Caret operator in documentation

Fixes jupyterlab#6885.

* Copy edit

* Updates caret tips

Mentions that minor and patch versions may be newer when `^` is used

docs/source/extension/extension_dev.rst

@@ -284,6 +284,8 @@ for another example of an extension that uses settings.
 
 Please ensure that the schema files are included in the ``files`` metadata in ``package.json``.
 
+When declaring dependencies on JupyterLab packages, use the ``^`` operator before a package version so that the build system installs the newest patch or minor version for a given major version. For example, ``^4.0.0`` will install version 4.0.0, 4.0.1, 4.1.0, etc.
+
 A system administrator or user can override default values provided in a plugin's settings schema file with the :ref:`overrides.json <overridesjson>` file.
 
 .. _disabledExtensions:
@@ -675,11 +677,14 @@ the CSS files) are watched by the WebPack process. This means that if
 your extension is in TypeScript you'll have to run a ``jlpm run build``
 before the changes will be reflected in JupyterLab. To avoid this step
 you can also watch the TypeScript sources in your extension which is
-usually assigned to the ``tsc -w`` shortcut. If WebPack doesn't seem to
+usually assigned to the ``tsc -w`` shortcut. If webpack doesn't seem to
 detect the changes, this can be related to `the number of available watches <https://github.com/webpack/docs/wiki/troubleshooting#not-enough-watchers>`__.
 
 Note that the application is built against **released** versions of the
-core JupyterLab extensions. If your extension depends on JupyterLab
+core JupyterLab extensions. You should specify the version using the ``^``
+operator, such as ``^4.0.0``, so that the build system can use newer minor and patch
+versions of a package with a particular major version.
+If your extension depends on JupyterLab
 packages, it should be compatible with the dependencies in the
 ``jupyterlab/static/package.json`` file.  Note that building will always use the latest JavaScript packages that meet the dependency requirements of JupyterLab itself and any installed extensions.  If you wish to test against a
 specific patch release of one of the core JupyterLab packages you can