egui_extras README grammar fixes
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-This is a crate that adds some features on top top of [`egui`](https://github.com/emilk/egui). This crate are for experimental features, and features that require big dependencies that does not belong in `egui`.
+This is a crate that adds some features on top top of [`egui`](https://github.com/emilk/egui). This crate is for experimental features, and features that require big dependencies that do not belong in `egui`.
