add price and footnote for Coursera

_vendors/coursera.yaml

@@ -2,7 +2,8 @@
 name: Coursera
 url: https://www.coursera.org
 base_pricing: $399 per u/y
-sso_pricing: Call Us! (min. 125 users)
-percent_increase: ???
+sso_pricing: $49875 per year[^coursera]
+footnotes: '[^coursera]: Coursera requires a minimum of 125 users to access SSO pricing. As they do not have an Enterprise price listed, this price just scales their lower cost tier up to 125 seats.'
+percent_increase: 12400%
 pricing_source: https://www.coursera.org/business/compare-plans
-updated_at: 2023-04-18
+updated_at: 2023-10-22