[doc] README: update

README.md

@@ -11,7 +11,7 @@ This repository contains all the sources of both the Opa compiler and the Opa li
 
 ## Getting Started ##
 
-Check out the [dedicated guide](https://github.com/MLstate/opalang/wiki/Getting-Started).
+Check out the [dedicated guide](https://github.com/MLstate/opalang/wiki/Getting-Opa).
 
 ## Quick build instructions ##
 
@@ -23,7 +23,7 @@ should get you there. `./configure` should report any missing dependencies and
 point you to the packages you may install to fix them (although those may depend
 on your distribution). `make` needs to be GNU make.
 
-The main dependency of Opa is OCaml 3.12 and Node.js >= 0.6. In case your distribution doesn't provide a recent enough version, or if you miss some other dependencies, you can use the `installation_helper.sh` script, which automates the download and
+The main dependencies of Opa is OCaml 3.12 and Node.js >= 0.6. In case your distribution doesn't provide a recent enough version, or if you miss some other dependencies, you can use the `installation_helper.sh` script, which automates the download and
 installation of our dependencies. Try
 
     $ tools/dependencies/installation_helper.sh --help