docs: add ProtoSchool markdown file to examples directory (#3173)

Adding a markdown file so ProtoSchool options will be surfaced to those looking for js-ipfs tutorial content in this directory. This links to a filtered list of ProtoSchool courses about IPFS. 

Co-authored-by: Alex Potsides <[email protected]>

Author: terichadbourne

.travis.yml

@@ -135,7 +135,7 @@ jobs:
         - npx json -I -f ./lerna.json -e "this.command.bootstrap.nohoist.push('ipfs-css', 'tachyons')"
         - npm run reset
         - npm install
-        - npm run build -- $RUN_SINCE --scope={ipfs,ipfs-http-client}
+        - npm run build -- --scope={ipfs,ipfs-http-client}
         - npm run test -- --scope=example* --concurrency=1
 
     - stage: release-rc-npm

examples/protoschool.md

@@ -0,0 +1,8 @@
+# IPFS Tutorials at ProtoSchool
+
+Explore [ProtoSchool's IPFS tutorials](https://proto.school/#/tutorials?course=ipfs) for interactive js-ipfs coding challenges, deep dives into DWeb concepts like content addressing, and more. 
+
+
+<a href="https://proto.school/#/tutorials?course=ipfs">
+<img src="https://user-images.githubusercontent.com/19171465/87574498-721e2f00-c69c-11ea-88f8-ca99fbdc73b6.png" href="https://proto.school/#/tutorials?course=ipfs" width="550" alt="screenshot of IPFS tutorials at ProtoSchool"/>
+</a>