docs: remove diamond sponsors from README

Author: mtrezza

README.md

@@ -32,10 +32,6 @@ The full documentation for Parse Server is available in the [wiki](https://githu
 
 A big *thank you* 🙏 to our [sponsors](#sponsors) and [backers](#backers) who support the development of Parse Platform!
 
-### Diamond Sponsors
-
-[![Diamond Sponsors](https://opencollective.com/parse-server/tiers/diamond-sponsor.svg?avatarHeight=70&button=false)](https://opencollective.com/parse-server/contribute/diamond-sponsor-10560)
-
 #### Bronze Sponsors
 
 [![Bronze Sponsors](https://opencollective.com/parse-server/tiers/bronze-sponsor.svg?avatarHeight=36&button=false)](https://opencollective.com/parse-server/contribute/bronze-sponsor-10559)
@@ -1186,4 +1182,4 @@ As of April 5, 2017, Parse, LLC has transferred this code to the parse-community
 [open-collective-link]: https://opencollective.com/parse-server
 [log_release]: https://github.com/parse-community/parse-server/blob/release/changelogs/CHANGELOG_release.md
 [log_beta]: https://github.com/parse-community/parse-server/blob/beta/changelogs/CHANGELOG_beta.md
-[log_alpha]: https://github.com/parse-community/parse-server/blob/alpha/changelogs/CHANGELOG_alpha.md
+[log_alpha]: https://github.com/parse-community/parse-server/blob/alpha/changelogs/CHANGELOG_alpha.md