Move wiki repo line down

Moved the wiki repo link down to the 'our repos' section. 

Also removed the link to the public wiki because we don't use it and the things on their are probably just a bit misleading. We should just delete it maybe?

Author: hannahkc

README.md

@@ -10,10 +10,6 @@ You can find:
 - user research findings in [research/](research/)
 - documentation of our designs in [design/](design/)
 
-We also have:
-- [a private wiki](https://github.com/alphagov/forms-team/wiki) for team documentation (set-up, onboarding etc)
-- [a public wiki](https://github.com/alphagov/forms/wiki) that we don't use all that much
-
 ## Our repositories
 
 You can find our code in the following repositories:
@@ -24,6 +20,9 @@ You can find our code in the following repositories:
 - [forms-prototypes](https://github.com/alphagov/forms-prototypes) - our prototypes, used for user research and design exploration.
 - [govuk-forms-markdown](https://github.com/alphagov/govuk-forms-markdown) - our gem for rendering the limited subset of markdown we support.
 
+We also have:
+- [a private wiki](https://github.com/alphagov/forms-team/wiki) for team documentation (set-up, onboarding etc)
+
 ## License
 
 Unless stated otherwise, the codebase is released under [the MIT License](LICENCE). This covers both the codebase and any sample code in the documentation.