[docs] clarify what "it" refers to (#4148)

* Update 03-loading.md

Edits ambiguous pronoun to make it clear that 'load' could run on either the client or the server.  I have seen a couple of tutorials recently with content creators stating the putting things like client secrets in this function within <script context="module"> is okay because it runs on the server.  If my understanding is correct, this is not safe and could possibly be made a little more clear.

* Update documentation/docs/03-loading.md

Co-authored-by: Ben McCann <322311+benmccann@users.noreply.github.com>

documentation/docs/03-loading.md

@@ -26,7 +26,7 @@ If the data for a page comes from its endpoint, you may not need a `load` functi
 
 > Note the `<script context="module">` — this is necessary because `load` runs before the component is rendered. Code that is per-component instance should go into a second `<script>` tag.
 
-`load` is similar to `getStaticProps` or `getServerSideProps` in Next.js, except that it runs on both the server and the client. In the example above, if a user clicks on a link to this page the data will be fetched from `cms.example.com` without going via our server.
+`load` is similar to `getStaticProps` or `getServerSideProps` in Next.js, except that `load` runs on both the server and the client. In the example above, if a user clicks on a link to this page the data will be fetched from `cms.example.com` without going via our server.
 
 If `load` returns `{fallthrough: true}`, SvelteKit will [fall through](/docs/routing#advanced-routing-fallthrough-routes) to other routes until something responds, or will respond with a generic 404.