Correct misspelling of Helm

Although it is spelling mistakes, it might make an affects
while reading.
Signed-off-by: Nguyen Hai Truong <truongnh@vn.fujitsu.com>

_proto/README.md

@@ -3,7 +3,7 @@ Protobuf3 type declarations for the Helm API
 
 Packages
 
- - `hapi.chart` Complete serialization of Heml charts
+ - `hapi.chart` Complete serialization of Helm charts
  - `hapi.release` Information about installed charts (Releases) such as metadata about when they were installed, their status, and how they were configured.
  - `hapi.services.rudder` Definition for the ReleaseModuleService used by Tiller to manipulate releases on a given node
  - `hapi.services.tiller` Definition of the ReleaseService provided by Tiller and used by Helm clients to manipulate releases cluster wide.