[MRG] migrate from .zenodo.json to CITATION.cff (#1037)

* migrate from .zenodo.json to CITATION.cff

* fix citation.cff syntax

.github/PULL_REQUEST_TEMPLATE.md

@@ -20,5 +20,5 @@ If applicable:
 - [ ] All CIs are happy
 - [ ] PR title starts with [MRG]
 - [ ] [whats_new.rst](https://github.com/mne-tools/mne-bids/blob/main/doc/whats_new.rst) is updated
-- [ ] New contributors have been added to [.zenodo.json](https://github.com/mne-tools/mne-bids/blob/main/.zenodo.json)
+- [ ] New contributors have been added to [CITATION.cff](https://github.com/mne-tools/mne-bids/blob/main/CITATION.cff)
 - [ ] PR description includes phrase "closes <#issue-number>"

.github/workflows/cffconvert.yml

@@ -0,0 +1,19 @@
+name: cffconvert
+
+on:
+  push:
+    paths:
+      - CITATION.cff
+
+jobs:
+  validate:
+    name: "validate"
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out a copy of the repository
+        uses: actions/checkout@v3
+
+      - name: Check whether the citation metadata from CITATION.cff is valid
+        uses: citation-file-format/cffconvert-github-action@2.0.0
+        with:
+          args: "--validate"