Add docs for a complete research workflow.

Closes #4

doc/source/chapter02_beginner-tutorial/awscli-config.rst

@@ -40,6 +40,8 @@ Running ``aws configure``, you will be asked 4 questions::
 
 "Access Key ID" and "Secret Access Key" are just like your AWS account name and password. For security reasons they are not the one you use to log into the console. You can obtain them in the "My Security Credentials" console. 
 
+.. _credentials-label:
+
 Obtaining security credentials
 ------------------------------
 

doc/source/chapter02_beginner-tutorial/quick-start.rst

@@ -33,6 +33,8 @@ In the EC2 console, make sure you are in the **US East (N. Virginia)** region as
 .. figure:: img/region_list.png
   :width: 300 px
 
+.. _choose_ami-label:
+
 In the EC2 console, click on "AMI" (Amazon Machine Image) under "IMAGES" on the left navigation bar. Then select "Public images" and search for **ami-08c83a8b3ebd20b63** or **GEOSChem_tutorial_20180926** – that's the system with GEOS-Chem installed. Select it and click on "Launch".
 
 .. figure:: img/search_ami.png
@@ -66,6 +68,8 @@ You can monitor your server in the EC2-Instance console. Within < 1min of initia
 
 You now have your own server running on the cloud!
 
+.. _login_ec2-label:
+
 Step 3: Log into the server and run GEOS-Chem
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@@ -192,6 +196,8 @@ We encourage users to try the new NetCDF diagnostics, but you can still use the
 
 Also, you could indeed download the output data and use old tools like IDL & MATLAB to analyze them, but we highly recommend the open-source Python/Jupyter/xarray ecosystem. It will vastly improve user experience and working efficiency, and also help open science and reproducible research.
 
+.. _terminate-label:
+
 Step 5: Shut down the server (Very important!!)
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