docs: Fix minor typo in i18n module docs

Signed-off-by: Philip Withnall <[email protected]>

Author: pwithnall

docs/markdown/i18n-module.md

@@ -83,7 +83,7 @@ i18n.xgettext(name, sources..., args: [...], recursive: false)
 ```
 
 Invokes the `xgettext` program on given sources, to generate a `.pot` file.
-This function is to be used when the `gettext` function workflow it not suitable
+This function is to be used when the `gettext` function workflow is not suitable
 for your project. For example, it can be used to produce separate `.pot` files
 for each executable.