Fix typos in egui docstrings (emilk#4869)

<!--
Please read the "Making a PR" section of
[`CONTRIBUTING.md`](https://github.com/emilk/egui/blob/master/CONTRIBUTING.md)
before opening a Pull Request!

* Keep your PR:s small and focused.
* The PR title is what ends up in the changelog, so make it descriptive!
* If applicable, add a screenshot or gif.
* If it is a non-trivial addition, consider adding a demo for it to
`egui_demo_lib`, or a new example.
* Do NOT open PR:s from your `master` branch, as that makes it hard for
maintainers to test and add commits to your PR.
* Remember to run `cargo fmt` and `cargo clippy`.
* Open the PR as a draft until you have self-reviewed it and run
`./scripts/check.sh`.
* When you have addressed a PR comment, mark it as resolved.

Please be patient! I will review your PR, but my time is limited!
-->

* [x] I have followed the instructions in the PR template (less the
self-review using the script as it's only a single word change).

crates/egui/src/context.rs

@@ -1668,7 +1668,7 @@ impl Context {
     /// Global zoom factor of the UI.
     ///
     /// This is used to calculate the `pixels_per_point`
-    /// for the UI as `pixels_per_point = zoom_fator * native_pixels_per_point`.
+    /// for the UI as `pixels_per_point = zoom_factor * native_pixels_per_point`.
     ///
     /// The default is 1.0.
     /// Make larger to make everything larger.

crates/egui/src/lib.rs

@@ -270,7 +270,7 @@
 //!
 //! ## Widget interaction
 //! Each widget has a [`Sense`], which defines whether or not the widget
-//! is sensitive to clickicking and/or drags.
+//! is sensitive to clicking and/or drags.
 //!
 //! For instance, a [`Button`] only has a [`Sense::click`] (by default).
 //! This means if you drag a button it will not respond with [`Response::dragged`].