Merge pull request #700 from nf-core/readme-update

Update README to mention guidelines

Author: jfy133

README.md

@@ -7,7 +7,7 @@ Test data to be used for automated testing with the nf-core pipelines
 
 nf-core is a collection of high quality Nextflow pipelines. This repository contains various files for CI and unit testing of nf-core pipelines and infrastructure.
 
-The principle for nf-core test data is as small as possible, as large as necessary. Always ask for guidance on the [nf-core slack](https://nf-co.re/join) before adding new test data.
+The principle for nf-core test data is as small as possible, as large as necessary. Please see the [guidelines](https://nf-co.re/docs/contributing/test_data_guidelines) for more detailed information. Always ask for guidance on the [nf-core slack](https://nf-co.re/join) before adding new test data.
 
 ## Documentation
 

docs/ADD_NEW_DATA.md

@@ -6,6 +6,7 @@ Please fill in the appropriate checklist below (delete whatever is not relevant)
    - If this is the case, follow the [documentation on how to use an existing test dataset](https://github.com/nf-core/test-datasets/blob/master/docs/USE_EXISTING_DATA.md)
  - [ ] Fork the [nf-core/test-datasets repository](https://github.com/nf-core/test-datasets) to your GitHub account
  - [ ] Create a new branch on your fork
+ - [ ] Check your proposed test data follows the [guidelines](https://nf-co.re/docs/contributing/test_data_guidelines)
  - [ ] Add your test dataset
    - [ ] If you clone it locally use `git clone <url> --branch <branch> --single-branch`
  - [ ] Make a PR on a new branch with a relevant name