[3.12] gh-127303: Add docs for token.EXACT_TOKEN_TYPES (GH-127304) (#127391)

gh-127303: Add docs for token.EXACT_TOKEN_TYPES (GH-127304)

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(cherry picked from commit dd3a87d2a8f8750978359a99de2c5cb2168351d1)

Co-authored-by: Илья Любавский <100635212+lubaskinc0de@users.noreply.github.com>
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
Co-authored-by: Tomas R. <tomas.roun8@gmail.com>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>