Fix line lengths in documentation and lint *.book files as JSON.

Summary: Fix a few "line too long" lint issues in the Diviner documentation. Also lint `*.book` files as JSON.

Test Plan: Eye-ball it.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9695

.arclint

@@ -32,6 +32,7 @@
     "json": {
       "type": "json",
       "include": [
+        "(^src/docs/book/.*\\.book$)",
         "(^support/jshint/jshintconfig$)",
         "(^\\.arcconfig$)",
         "(^\\.arclint$)",

src/docs/contributor/general_coding_standards.diviner

@@ -69,7 +69,8 @@ gather concrete performance data.
   - Follow language-specific conventions.
   - Name things unambiguously.
   - Choose descriptive names.
-  - Avoid nonstandard abbreviations (common abbreviations like ID, URI and HTTP are fine).
+  - Avoid nonstandard abbreviations (common abbreviations like ID, URI and HTTP
+    are fine).
   - Spell words correctly.
   - Use correct grammar.
 

src/docs/contributor/php_coding_standards.diviner

@@ -1,7 +1,8 @@
 @title PHP Coding Standards
 @group standards
 
-This document describes PHP coding standards for Phabricator and related projects (like Arcanist and libphutil).
+This document describes PHP coding standards for Phabricator and related
+projects (like Arcanist and libphutil).
 
 = Overview =
 

src/docs/flavor/writing_reviewable_code.diviner

@@ -79,8 +79,8 @@ reviewing big checkins.
 
 = Write Sensible Commit Messages =
 
-There are lots of resources for this on the internet. All of them say pretty much
+There are lots of resources for this on the internet. All of them say pretty
-the same thing; this one does too.
+much the same thing; this one does too.
 
 The single most important thing is: **commit messages should explain //why// you
 are making the change**.

src/docs/user/userguide/arcanist_lint_unit.diviner

@@ -37,8 +37,9 @@ make this work, you need to do three things:
 = Create a libphutil Library =
 
 If you haven't created a library for the class to live in yet, you need to do
-that first. Follow the instructions in @{article:libphutil Libraries User Guide},
+that first. Follow the instructions in
-then make the library loadable by adding it to your ##.arcconfig## like this:
+@{article:libphutil Libraries User Guide}, then make the library loadable by
+adding it to your ##.arcconfig## like this:
 
   {
     // ...

src/docs/user/userguide/diviner.diviner

@@ -45,9 +45,9 @@ look like this:
 
 The properties in this file are:
 
-  - `name`: Required. Short, unique name to identify the documentation book. This
+  - `name`: Required. Short, unique name to identify the documentation book.
-    will be used in URIs, so it should not have special characters. Good names
+    This will be used in URIs, so it should not have special characters. Good
-    are things like `"example"` or `"libcabin"`.
+    names are things like `"example"` or `"libcabin"`.
   - `root`: Required. The root directory (relative to the `.book` file) which
     documentation should be generated from. Often this will be a value like
     `"../../"`, to specify the project root (for example, if the `.book` file