Split Getting Started docs into separate sections

The "Getting Started" docs became overly long and unwieldy over time.
This splits it into separate sections, including:

* Quickstart
* Installation
* Writing content
* Publish your site

docs/quickstart.rst

@@ -0,0 +1,73 @@
+Quickstart
+##########
+
+Reading through all the documentation is highly recommended, but for the truly
+impatient, following are some quick steps to get started.
+
+Installation
+------------
+
+Install Pelican on Python 2.7.x or Python 3.3+ by running the following command
+in your preferred terminal, prefixing with ``sudo`` if permissions warrant::
+
+    pip install pelican markdown
+
+Create a project
+----------------
+
+First, choose a name for your project, create an appropriately-named directory
+for your it, and switch to that directory::
+
+    mkdir -p ~/projects/yoursite
+    cd ~/projects/yoursite
+
+Create a skeleton project via the ``pelican-quickstart`` command, which begins
+by asking some questions about your site::
+
+    pelican-quickstart
+
+For questions that have default values denoted in brackets, feel free to use
+the Return key to accept those default values. When asked for your URL prefix,
+enter your domain name as indicated (e.g., ``http://example.com``).
+
+Create an article
+-----------------
+
+You cannot run Pelican until you have created some content. Use your preferred
+text editor to create your first article with the following content::
+
+    Title: My First Review
+    Date: 2010-12-03 10:20
+    Category: Review
+
+    Following is a review of my favorite mechanical keyboard.
+
+Given that this example article is in Markdown format, save it as
+``~/projects/yoursite/content/keyboard-review.md``.
+
+Generate your site
+------------------
+
+From your project directory, run the ``pelican`` command to generate your site::
+
+    pelican content
+
+Your site has now been generated inside the ``output`` directory. (You may see a
+warning related to feeds, but that is normal when developing locally and can be
+ignored for now.)
+
+Preview your site
+-----------------
+
+Open a new terminal session and run the following commands to switch to your
+``output`` directory and launch Python's built-in web server::
+
+    cd ~/projects/yoursite/output
+    python -m SimpleHTTPServer
+
+Preview your site by navigating to http://localhost:8000/ in your browser.
+
+Continue reading the other documentation sections for more detail, and check out
+the Pelican wiki's Tutorials_ page for links to community-published tutorials.
+
+.. _Tutorials: https://github.com/getpelican/pelican/wiki/Tutorials