CONTRIBUTING-DOCUMENTATION.adoc edit

I made it be more formal and be easier to read.

Closes gh-1512

CONTRIBUTING-DOCUMENTATION.adoc

@@ -1,4 +1,4 @@
-= How to contribute to the reference manual
+= How to Contribute to the Reference Manual
 
 The Spring Framework reference manual uses http://asciidoctor.org/[asciidoctor]. This
 document describes how to contribute documentation updates.
@@ -13,14 +13,16 @@ from the project root execute the following command:
 	./gradlew asciidoctor
 ----
 
-The generated reference manual will then be available at `build/asciidoc/html5/index.html`.
+The generated reference manual will then be available at
+`build/asciidoc/html5/index.html`.
 
 == Live Editing
 
-One of the nice features about using asciidoctor is the support for live editing.
+One of the nice features about using Asciidoctor is the support for live editing.
 
-You will find a Guardfile already present at `spring-framework/src/asciidoc/Guardfile`.
-Make sure first to follow the setup instructions within the
+You will find a Guardfile already present at
+`spring-framework/src/docs/asciidoc/Guardfile`. First, follow the setup instructions
+within the
 http://asciidoctor.org/docs/editing-asciidoc-with-live-preview/[Editing AsciiDoc
 with Live Preview] document. Once you have done that, there are additional gems to
 install to make it work (assuming that you are using http://livereload.com/[LiveReload]):
@@ -31,26 +33,28 @@ install to make it work (assuming that you are using http://livereload.com/[Live
 ----
 
 When running `guard start` within the `src/asciidoc/` folder, any changes to the
-`src/asciidoc/index.adoc` file will automatically be written to
+`src/asciidoc/index.adoc` file are automatically written to
 `src/asciidoc/build/index.html`.
 
 == Troubleshooting
 
-* If you are using LiveReload, make sure to select _Allow access to file URLs_ in the
+* If you are using LiveReload, select _Allow access to file URLs_ in the
 LiveEdit plugin options of your browser.
 * The icon used to enable _LiveReload_ can be a bit confusing. The dot is empty when it
 is disabled and full when the plugin is active. Make sure to enable it on the tab
 displaying the `index.html` file.
-* Ensure you are _not_ running `guard start` at all as two instances could not run at the
-same time. To exit a current session in a clean way, type `e` in the shell.
+* Ensure you are _not_ running `guard start` at all, as two instances could not run at
+the same time. To exit a current session in a clean way, type `e` in the shell.
 
 == Documentation Notes
 
 Some notes on the documentation.
 
-* Documentation is wrapped at 90 chars; ensure that you manually wrap your edits.
-* Tabs are used for indentation; do not use spaces.
+* Documentation is wrapped at 90 chars. Ensure that you manually wrap your edits.
+* Tabs are used for indentation. Do not use spaces.
 * Follow the existing style when inserting `source` blocks.
+
+Here are some useful resources for working with Asciidoctor:
 * http://asciidoctor.org/docs/asciidoc-syntax-quick-reference/[Asciidoctor Quick Reference]
 * http://asciidoctor.org/docs/user-manual/[Asciidoctor Manual]
 * http://asciidoctor.org/docs/asciidoc-writers-guide/[Asciidoctor Writers Guide]