Update CHANGELOG.md and CONTRIBUTING.md

Author: codeclown

CHANGELOG.md

@@ -1,11 +1,15 @@
 # Changelog
 
-## Upcoming
+## 1.5.0
 
 Features:
 - New `.urlParams()` method for easy param substitution (c7f2ff3)
 - TypeScript type definitions (4beec22)
 
+## 1.4.0
+
+Malformed release due to author messing up commits.
+
 ## 1.3.0
 
 Features:

CONTRIBUTING.md

@@ -14,3 +14,27 @@ Documentation of all methods should be kept up-to-date in two places:
 ## Changelog
 
 Each change should be complemented with a bulletpoint in CHANGELOG.md under "Upcoming".
+
+## Release process
+
+Make sure to build latest sources (open issue #16):
+
+```shell
+$ yarn build
+```
+
+Bump up the version:
+
+```shell
+$ yarn version
+info Current version: 1.3.0
+question New version:
+```
+
+Publish on npm:
+
+```shell
+yarn publish
+```
+
+Remember to update CHANGELOG.md.