doc: update profiles documentation

Rewrite the descriptions for sections.

Use pre-formatted text for technical values or file paths.

Simplify example Python code.

Remove pyxdg TODO item, since Koji never used the xdg specification for
configurations, and this would break backwards compatibility at this
point.

docs/source/profiles.rst

@@ -1,74 +1,81 @@
 =============
 Koji Profiles
 =============
-This document describes how to work with koji profiles.
+
+Koji clients can connect to multiple Koji instances via "profiles". These are
+configuration sections that describe how to connect to different environments.
 
 
 Command Line Interface
 ======================
-Koji client allows connecting to multiple koji instances from CLI
-by using profiles. The default profile is given by executable file name,
-which is 'koji'.
 
-To change koji profile, you can:
+By default, the ``koji`` CLI will use a profile named ``koji``. (This profile
+is Fedora's production Koji environment.)
 
- * run koji with --profile=$profile_name argument
- * change executable file name by symlinking $profile_name -> koji
+You can choose a different profile on the CLI. For example, to choose CentOS's
+"cbs" profile instead:
 
+ * Run ``koji`` with ``--profile=cbs``, for example ``koji --profile cbs
+   list-hosts``.
+
+ * Symlink or alias the profile name to the ``koji`` executable. For example,
+   ``ln -s /usr/bin/koji /usr/bin/cbs`` or ``alias cbs=koji``. The CLI will
+   use the executable name as the profile name, so you can simply run ``cbs
+   list-hosts``.
 
 Configuration Files
 ===================
-Configuration files are located in following locations:
 
- * /etc/koji.conf
- * /etc/koji.conf.d/\*.conf
- * ~/.koji/config.d/\*.conf
- * user-specified config
+The Koji client searches for profile definitions in the following locations:
 
-Koji reads them, looking for [$profile_name] sections.
+ * ``/etc/koji.conf``
+ * ``/etc/koji.conf.d/*.conf``
+ * ``~/.koji/config.d/*.conf``
+ * The ``--config=FILE`` option on the CLI
 
+Koji reads all these files and searches for ``[$profile_name]`` sections. For
+example, if you use a profile named ``cbs``, the Koji client will search for a
+section titled ``[cbs]`` in the files.
 
 Using Koji Profiles in Python
 =============================
-Instead of using koji module directly,
-get profile specific module by calling::
 
-    >>> mod = koji.get_profile_module($profile_name)
+Instead of using the ``koji`` Python module directly, you can get a
+profile-specific module by calling::
 
-This module is clone of koji module with additional
-profile specific tweaks.
+    mykoji = koji.get_profile_module("cbs")
 
-Profile configuration is available via::
+This ``mykoji`` module is clone of the ``koji`` module with additional
+profile-specific tweaks.
 
-    >>> mod.config
+You can read all the settings in the profile configuration with the
+``.config`` property::
+
+    mykoji.config        # optparse.Values object
+    vars(mykoji.config)  # plain python dict
 
 
-Example
--------
+Examples
+--------
 
-Print configuration::
+Print configurations for multiple profiles::
 
     import koji
 
     fedora_koji = koji.get_profile_module("koji")
-    ppc_koji = koji.get_profile_module("ppc-koji")
+    stage_koji = koji.get_profile_module("stg")
 
-    for i in (fedora_koji, ppc_koji):
-        print("PROFILE: %s" % i.config.profile)
-        for key, value in sorted(i.config.__dict__.items()):
+    for this_koji in (fedora_koji, stage_koji):
+        print("PROFILE: %s" % this_koji.config.profile)
+        for key, value in sorted(vars(this_koji.config).items()):
             print("    %s = %s" % (key, value))
         print("")
 
 
-Use ClientSession::
+Use ``ClientSession`` to send RPCs to the hub::
 
     import koji
 
-    koji_module = koji.get_profile_module("koji")
-    client = koji_module.ClientSession(koji_module.config.server)
+    mykoji = koji.get_profile_module("koji")
+    client = mykoji.ClientSession(mykoji.config.server)
     print(client.listTags())
-
-
-TODO
-====
-* consider using pyxdg for user config locations