Clarify Vale rules for contractions
Issue Description
Vale is inconsistent regarding the use of contractions:
Use "should not" instead of "shouldn't" , for a friendly, informal tone. Use "does not" instead of "doesn't", for a friendly, informal tone. Use "you're" instead of "you are", for a friendly, informal tone.
(Vale rules: /doc/.vale/gitlab/Contractions.yml)
This also appears to be inconsistent with our docs guidelines.
Edited by Mike Lewis