Add tips on releasing a new library version. (#631)

CONTRIBUTING.md

@@ -4,3 +4,20 @@ Please read the [Contribution Guide](https://github.com/stellar/docs/blob/master
 
 Then please [sign the Contributor License Agreement](https://docs.google.com/forms/d/1g7EF6PERciwn7zfmfke5Sir2n10yddGGSXyZsq98tVY/viewform?usp=send_form).
 
+
+# Releasing
+Just like with the [js-stellar-base](https://github.com/stellar/js-stellar) library, there are a few important things to remember when releasing a new version of the library.
+
+In fact, you should follow [the steps there](https://github.com/stellar/js-stellar/base/blob/master/CONTRIBUTING.md#Releasing), first, except for this repository. Then, **if base has been updated**, you want to follow the additional steps here:
+
+ - [ ] First, bump its version accordingly. This is straightforward: change the version field of `"stellar-base"` under the `"dependencies"` section in the SDK's [package.json](https://github.com/stellar/js-stellar-sdk/blob/master/package.json#L140), e.g.:
+
+```diff
+  "dependencies": {
+     ...
+-    "stellar-base": "^1.0.0",
++    "stellar-base": "^2.0.0",
+  }
+```
+
+  - [ ] Finally, run `yarn` so that the dependency is pulled (ensuring its a valid version) and the lockfile is updated with the latest integrity details. You can now commit the change and PR accordingly.