Add release instructions

RELEASE.md

@@ -0,0 +1,50 @@
+# How to create new release
+
+## Integrate changes and test them
+
+All PRs that go into the release should be merged to master and tested
+accordingly.
+
+## Bump the version number
+
+Bump the version number in package.json and commit the change.
+
+Use "Bump version to x.x.x" commit message.
+
+Given a version number MAJOR.MINOR.PATCH, increment the:
+
+ * MAJOR version when you make incompatible API changes,
+ * MINOR version when you add functionality in a backwards compatible manner, and
+ * PATCH version when you make backwards compatible bug fixes.
+
+Read more at [semver.org](https://semver.org/).
+
+## Tag the release
+
+Now that you have created the version bump commit, tag it with the release name. For example:
+
+```
+git tag v2.1.2
+```
+
+## Push the changes and tags
+
+```
+git push origin master
+git push --tags origin
+```
+
+## Edit the relase at Github
+
+Find the release at [Releases
+page](https://github.com/sematext/sematable/releases) and edit it if necessary
+to add more information about the changes that were made. For minor and patch
+releases this is usually not required.
+
+## Publish the release
+
+```
+npm publish
+```
+
+Go to the Releases page, edit the release and click "Publish release"