Add Correct Preview Agreement to foundation/join (graphql#1395)

Author: jorydotcom

src/content/foundation/Join.md

@@ -60,7 +60,7 @@ The first 20 members of the GraphQL Foundation participate as voting members of
 To [join the GraphQL Foundation](https://join.graphql.org), organizations become a member of the Linux Foundation and sign the GraphQL Foundation participation agreement. The GraphQL Foundation annual fee is received into a fund managed by the GraphQL Foundation Governing Board.
 
 * [Preview the Linux Foundation membership application »](/files/LF_Membership-Preview.pdf)
-* [Preview the GraphQL Foundation participation agreement »](/files/GraphQL_Foundation-Participation_Agreement-Preview.pdf)
+* [Preview the GraphQL Foundation participation agreement »](/files/foundation-participation-agreement-revised-jan-2022.pdf)
 
 GraphQL Foundation membership fees and Linux Foundation Silver Membership dues are adjusted according to an organization's number of full-time employees.