Merge pull request #252 from mattbostock/use-v3-api

Prefer v3 API for Puppet Forge and clarify README

README.md

@@ -55,7 +55,7 @@ as if the Puppetfile contained
 
 ### Example Puppetfile
 
-    forge "https://forge.puppetlabs.com"
+    forge "https://forgeapi.puppetlabs.com"
 
     mod 'puppetlabs-razor'
     mod 'puppetlabs-ntp', "0.0.3"
@@ -77,7 +77,7 @@ When fetching a module all dependencies specified in its
 
 ### Puppetfile Breakdown
 
-    forge "https://forge.puppetlabs.com"
+    forge "https://forgeapi.puppetlabs.com"
 
 This declares that we want to use the official Puppet Labs Forge as our default
 source when pulling down modules.  If you run your own local forge, you may
@@ -167,10 +167,10 @@ source specified.  This command writes the complete resolution into
 Librarian-puppet support both v1 and v3 of the Puppet Forge API.
 Specify a specific API version when installing modules:
 
-    $ librarian-puppet install --use-v1-api # this is default
-    $ librarian-puppet install --no-use-v1-api # use the v3 API
+    $ librarian-puppet install --use-v1-api # this is default; ignored for official Puppet Forge
+    $ librarian-puppet install --no-use-v1-api # use the v3 API; default for official Puppet Forge
 
-Please note that this does not apply for the official Puppet Forge where v3 is used by default.
+Please note that this does not apply for the official Puppet Forge, where v3 is used by default.
 
 Get an overview of your `Puppetfile.lock` with: