Tweaks to plugin marketplace (#2209)

* Tweaks to plugin marketplace

* Add plugin details to roadmap

* Update README.md

* Link to plugins from home

* Update circleci.yaml

microsite/data/plugins/api-docs.yaml

@@ -5,5 +5,5 @@ authorUrl: https://sda.se/
 category: Discovery
 description: Components to discover and display API entities as an extension to the catalog plugin.
 documentation: https://github.com/spotify/backstage/blob/master/plugins/api-docs/README.md
-iconUrl: https://github.com/spotify/backstage/raw/master/plugins/api-docs/docs/entity_tab_api.png
+iconUrl: https://thecoders.io/wp-content/uploads/2019/11/tech-swagger.svg
 npmPackageName: '@backstage/plugin-api-docs'

microsite/data/plugins/circleci.yaml

@@ -5,5 +5,5 @@ authorUrl: https://www.spotify.com/
 category: CI
 description: Automate your development process with CI hosted in the cloud or on a private server.
 documentation: https://github.com/spotify/backstage/tree/master/plugins/circleci
-iconUrl: https://d3r49iyjzglexf.cloudfront.net/logo-wordmark-26f8eaea9b0f6e13b90d3f4a8fd8fda31490f5af41daab98bbede45037682576.svg
+iconUrl: https://www.saaves.com/storage/brochure/logo-circleci-icon1583764538.png
 npmPackageName: '@backstage/plugin-circleci'

microsite/data/plugins/github-actions.yaml

@@ -0,0 +1,13 @@
+---
+title: GitHub Actions
+author: Spotify
+authorUrl: https://www.spotify.com/
+category: CI
+description: GitHub Actions makes it easy to automate all your software workflows, now with world-class CI/CD. Build, test, and deploy your code right from GitHub.
+documentation: https://github.com/spotify/backstage/tree/master/plugins/github-actions
+iconUrl: https://avatars2.githubusercontent.com/u/44036562?s=400&v=4
+npmPackageName: '@backstage/plugin-github-actions'
+tags:
+  - ci
+  - cd
+  - github

microsite/data/plugins/tech-radar.yaml

@@ -5,5 +5,5 @@ authorUrl: https://www.spotify.com/
 category: Discovery
 description: Visualize the your company's official guidelines of different areas of software development.
 documentation: https://github.com/spotify/backstage/tree/master/plugins/tech-radar
-iconUrl: https://github.com/spotify/backstage/raw/master/plugins/tech-radar/docs/screenshot.png
+iconUrl: https://img.icons8.com/officel/2x/radar.png
 npmPackageName: '@backstage/plugin-tech-radar'