Fix typos (#1156)

CITING-SOURCES.md

@@ -23,9 +23,9 @@ from detecting them as macros.
   titled `References`.
 
 Note that entries in the BibLaTeX file are expected to have all of the
-apropriate fields defined according to their type. For instance, `@book`s _must_
-have a defined field for `publisher` and `year`. If this information is not
-available, please define them as empty fields. E.g. `publisher = {},`.
+appropriate fields defined according to their type. For instance, `@book`s
+_must_ have a defined field for `publisher` and `year`. If this information is
+not available, please define them as empty fields. E.g. `publisher = {},`.
 
 If you are unsure about how to structure your BibLaTeX entry, it may be useful
 to know that the references are checked by the `linkcheck` GitHub workflow, so

STATEMENT-OF-INCLUSION.md

@@ -9,7 +9,7 @@ from us that we are kind and respectful in discussions, that we will be mindful
 of your pronouns and use
 [inclusive language](https://www.apa.org/about/apa/equity-diversity-inclusion/language-guidelines),
 and that we value your input regardless of your level of experience or status in
-the community. We're commited to providing a safe and welcoming environment to
+the community. We're committed to providing a safe and welcoming environment to
 people of any gender identity, sexual orientation, race, colour, age, ability,
 ethnicity, background, or fluency in English -- here on GitHub, in online
 communication channels, and in person. Homotopy type theory is difficult enough