Update contributors guidelines.

It had unrelated information copied from main Spree repo, also markdown
should not have hardcoded newlines within text.

CONTRIBUTING.md

@@ -1,15 +1,13 @@
-Spree Paypal Express is an open source project and we encourage contributions.  Please see the
-[contributors guidelines](http://spreecommerce.com/documentation/contributing_to_spree.html)
-before contributing.
+Spree Paypal Express is an open source project and we encourage contributions.  Please see the [contributors guidelines](http://spreecommerce.com/documentation/contributing_to_spree.html) for more information before contributing.
 
 ## Filing an issue
 
 When filing an issue on this extension, please first do these things:
 
 * Verify you can reproduce this issue in a brand new application.
-* Include the `httplog` in that application's Gemfile.
+* Include the `httplog` in that application's `Gemfile`.
 * Run through the steps to reproduce the issue again.
-* Create a Gist which contains the complete output from the server during the course of these transactions.
+* Create a `Gist` which contains the complete output from the server during the course of these transactions.
 
 This information will help us replicate what's going wrong on the PayPal side of things.
 
@@ -20,51 +18,33 @@ In the issue itself please provide:
 * The version of Spree *and* the version of Rails.
 * A list of all extensions.
 * Any relevant stack traces ("Full trace" preferred)
-* Your Gemfile
+* Your `Gemfile`
 
-In 99% of cases, this information is enough to determine the cause and solution
-to the problem that is being described.
+In 99% of cases, this information is enough to determine the cause and solution to the problem that is being described.
 
-Please remember to format code using triple backticks (\`) so that it is neatly
-formatted when the issue is posted.
-
-Any issue that is open for 14 days without actionable information or activity
-will be marked as "stalled" and then closed. Stalled issues can be re-opened if
-the information requested is provided.
+Please remember to format code using triple ``backticks (`)`` so that it is neatly formatted when the issue is posted.
 
 ## Pull requests
 
-We gladly accept pull requests to fix bugs and, in some circumstances, add new
-features to this extension.
+We gladly accept pull requests to fix bugs and, in some circumstances, add new features to this extension.
 
 Here's a quick guide:
 
 1. Fork the repo.
 
-2. Run the tests. We only take pull requests with passing tests, and it's great
-to know that you have a clean slate:
-
-        $ bash build.sh
+2. Run the tests. We only take pull requests with passing tests, and it's great to know that you have a clean slate.
 
-3. Create new branch then make changes and add tests for your changes. Only
-refactoring and documentation changes require no new tests. If you are adding
-functionality or fixing a bug, we need tests!
+3. Create new branch then make changes and add tests for your changes. Only refactoring and documentation changes require no new tests. If you are adding functionality or fixing a bug, we need tests!
 
-4. Push to your fork and submit a pull request. If the changes will apply cleanly
-to the latest stable branches and master branch, you will only need to submit one
-pull request.
+4. Push to your fork and submit a pull request. If the changes will apply cleanly to the latest stable branches and master branch, you will only need to submit one pull request.
 
-At this point you're waiting on us. We like to at least comment on, if not
-accept, pull requests within three business days (and, typically, one business
-day). We may suggest some changes or improvements or alternatives.
+At this point you're waiting on us. We may suggest some changes or improvements or alternatives.
 
-Some things that will increase the chance that your pull request is accepted,
-taken straight from the Ruby on Rails guide:
+Some things that will increase the chance that your pull request is accepted, taken straight from the Ruby on Rails guide:
 
 * Use Rails idioms and helpers
 * Include tests that fail without your code, and pass with it
-* Update the documentation, the surrounding one, examples elsewhere, guides,
-  whatever is affected by your contribution
+* Update the documentation, the surrounding one, examples elsewhere, guides, whatever is affected by your contribution
 
 Syntax: