style(docs): improve readability of publish_docs (#2015)

Break down the script into multiple lines, but remaining the
ampersands so it fails if any part of the command fails

Author: igncp

publish_docs.sh

@@ -3,4 +3,13 @@
 # Generates documentation and pushes it up to the site
 # WARNING: Do NOT run this script unless you have remote `upstream` set properly
 #
-rm -rf tmp/docs && npm run build_docs && git checkout gh-pages && git fetch upstream && git rebase upstream/gh-pages && cp -r ./tmp/docs/ ./ && rm -rf tmp/ && git add . && git commit -am "chore(docs): docs generated automatically" && git push upstream gh-pages
+rm -rf tmp/docs && \
+  npm run build_docs && \
+  git checkout gh-pages && \
+  git fetch upstream && \
+  git rebase upstream/gh-pages && \
+  cp -r ./tmp/docs/ ./ && \
+  rm -rf tmp/ && \
+  git add . && \
+  git commit -am "chore(docs): docs generated automatically" && \
+  git push upstream gh-pages