corrected use of verbatim notation

doc/overview.edoc

@@ -21,9 +21,9 @@ actively use either, they are no longer fetched by default.
 
 <h2>Installation</h2>
 
-You can get `gproc` from the <a href="https://hex.pm/packages/gproc">Hex package manager</a>
+You can get `gproc' from the <a href="https://hex.pm/packages/gproc">Hex package manager</a>
 
-That means declaring dependency on `{gproc, "0.5.0"}` in your `rebar` based applications or `{:gproc, "~> 0.5.0"}` in your `mix` based applications.
+That means declaring dependency on `{gproc, "0.5.0"}' in your `rebar3'-based applications or `{:gproc, "~> 0.5.0"}' in your `mix' based applications.
 
 <h2>Introduction</h2>