Fixes typo in toolchains documentation page
## Intent
To fix what I believe it's a typo in `site/en/docs/toolchains.md`.
Closes
@@ -450,7 +450,7 @@ with preference given to earlier items in the list.
The resolution steps are as follows.
1. A `target_compatible_with` or `exec_compatible_with` clause *matches* a
- platform iff, for each `constraint_value` in its list, the platform also has
+ platform if, for each `constraint_value` in its list, the platform also has
that `constraint_value` (either explicitly or as a default).
If the platform has `constraint_value`s from `constraint_setting`s not
