Document prettyPrintLegacyAssemblyJSON in the README

Author: axic

README.md

@@ -181,3 +181,14 @@ var outputABI = abi.update('0.3.6', inputABI)
 // Output contains: [{"constant":false,"inputs":[],"name":"hello","outputs":[{"name":"","type":"string"}],"payable":true,"type":"function"},{"type":"fallback","payable":true}]
 
 ```
+
+### Formatting old JSON assembly output
+
+There is a helper available to format old JSON assembly output into a text familiar to earlier users of Remix IDE.
+
+```
+var translate = require('solc/translate')
+
+// assemblyJSON refers to the JSON of the given assembly and sourceCode is the source of which the assembly was generated from
+var output = translate.prettyPrintLegacyAssemblyJSON(assemblyJSON, sourceCode)
+```