Remove arcanist projects from documentation

Summary: Ref T7604. Remove references to "arcanist projects" from documentation.

Test Plan: N/A

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7604

Differential Revision: https://secure.phabricator.com/D13005

src/docs/user/userguide/arcanist_new_project.diviner

@@ -49,10 +49,6 @@ Other options include:
     See below for details about path resolution, or see
     @{article:libphutil Libraries User Guide} for a general introduction to
     libphutil libraries.
-  - **project.name**: name an "Arcanist Project" to associate this working
-    copy (Git, Mercurial) or directory (SVN) with. Previously, this was a
-    required option, but `arc` can now usually operate without it in Git and
-    Mercurial. This option was previously called `project_id`.
   - **https.cabundle**: specifies the path to an alternate certificate bundle
     for use when making HTTPS connections.
   - **lint.engine**: the name of a subclass of

src/docs/user/userguide/arcanist_quick_start.diviner

@@ -44,12 +44,9 @@ Create a `.arcconfig` file in your project's working copy:
   yourproject/ $ $EDITOR .arcconfig
   yourproject/ $ cat .arcconfig
   {
-    "project.name" : "yourprojectname",
     "phabricator.uri" : "https://phabricator.example.com/"
   }
 
-Set `project.name` to a string that identifies the project.
-
 Set `phabricator.uri` to the URI for your Phabricator install (where `arc`
 should send changes to).
 

src/docs/user/userguide/libraries.diviner

@@ -83,7 +83,6 @@ Phabricator. For example, you might write this file to
 `libcustom/.arcconfig`:
 
   {
-    "project.name" : "libcustom",
     "load": [
       "phabricator/src/"
     ]