Modernize Arcanist documentation

Summary: Change `project_id` to `project.name` and `conduit_uri` to `phabricator.uri`.

Test Plan: `grep`

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9736

src/docs/user/configuration/advanced_configuration.diviner

@@ -25,7 +25,7 @@ to lowest priority:
     running `bin/config`.
   - **Config Files**: Values are stored in a config file in `conf/`. The file
     to use is selected by writing to `conf/local/ENVIRONMENT`, or setting the
-    PHABRICATOR_ENV configuration variable. See below for more information.
+    `PHABRICATOR_ENV` configuration variable. See below for more information.
   - **Defaults**: Defaults hard-coded in the Phabricator source, which can not
     be edited. They have the lowest priority, and all other settings override
     them.

src/docs/user/userguide/arcanist_new_project.diviner

@@ -149,7 +149,7 @@ relative path like this:
 ...arc looks for it by trying these paths:
 
   - `path/to/root/examplelib/src/` First, arc looks in the project's root
-    directory (where the .arcconfig lives) to see if the library is part of
+    directory (where the `.arcconfig` lives) to see if the library is part of
     the project. This makes it easy to just put project-specific code in a
     project.
   - `path/to/root/../examplelib/src/` Next, arc looks //next to// the project's

src/docs/user/userguide/arcanist_quick_start.diviner

@@ -44,13 +44,13 @@ Create a `.arcconfig` file in your project's working copy:
   yourproject/ $ $EDITOR .arcconfig
   yourproject/ $ cat .arcconfig
   {
-    "project_id" : "yourprojectname",
+    "project.name" : "yourprojectname",
-    "conduit_uri" : "https://phabricator.example.com/"
+    "phabricator.uri" : "https://phabricator.example.com/"
   }
 
-Set `project_id` to a string that identifies the project.
+Set `project.name` to a string that identifies the project.
 
-Set `conduit_uri` to the URI for your Phabricator install (where `arc`
+Set `phabricator.uri` to the URI for your Phabricator install (where `arc`
 should send changes to).
 
 NOTE: You should **commit this file** to the repository.

src/docs/user/userguide/libraries.diviner

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