docs: update link to features board --> ideas (#586)

README.md

@@ -19,7 +19,7 @@ If you are looking for help, please take a look at the [Documentation Website](h
 Contributing
 ------------
 
-We would love your contributions to Central. If you have thoughts or suggestions, please share them with us on the [Features board](https://forum.getodk.org/c/features) on the ODK Forum. If you wish to contribute code, you have the option of working on the Backend server ([contribution guide](https://github.com/getodk/central-backend/blob/master/CONTRIBUTING.md)), the Frontend website ([contribution guide](https://github.com/getodk/central-frontend/blob/master/CONTRIBUTING.md)), or both. To set up a development environment, first follow the [Backend instructions](https://github.com/getodk/central-backend#setting-up-a-development-environment) and then optionally the [Frontend instructions](https://github.com/getodk/central-frontend#setting-up-your-development-environment).
+We would love your contributions to Central. If you have thoughts or suggestions, please share them with us on the [Ideas board](https://forum.getodk.org/c/ideas) on the ODK Forum. If you wish to contribute code, you have the option of working on the Backend server ([contribution guide](https://github.com/getodk/central-backend/blob/master/CONTRIBUTING.md)), the Frontend website ([contribution guide](https://github.com/getodk/central-frontend/blob/master/CONTRIBUTING.md)), or both. To set up a development environment, first follow the [Backend instructions](https://github.com/getodk/central-backend#setting-up-a-development-environment) and then optionally the [Frontend instructions](https://github.com/getodk/central-frontend#setting-up-your-development-environment).
 
 The `master` branch of this repository is a stable branch that users clone when they install Central in production. The `next` branch reflects ongoing development for the next version of Central. Note that this differs from the `central-backend` and `central-frontend` repositories, where `master` is the development branch. If you create a PR to this repository, please target the `next` branch unless you are only changing documentation like the readme.