Fix up typos

Ran automated checker for common typos [1]. Most of these changes have
no functional change *except* for `./ci/sim_run.sh` where, previously
the `bootstrap` feature wasn't being selected properly.

I didn't touch anything in the `./ext/` folder as anything in there
should probably be fixed in the upstream repo.

[1] https://github.com/codespell-project/codespell

Signed-off-by: Sam Bristow <sam@bristow.nz>
diff --git a/sim/simflash/src/lib.rs b/sim/simflash/src/lib.rs
index 2c797dd..43b6232 100644
--- a/sim/simflash/src/lib.rs
+++ b/sim/simflash/src/lib.rs
@@ -83,7 +83,7 @@
 }
 
 /// An emulated flash device.  It is represented as a block of bytes, and a list of the sector
-/// mapings.
+/// mappings.
 #[derive(Clone)]
 pub struct SimFlash {
     data: Vec<u8>,