Add support for sub-organization specific themes

By default website will just be affiliated with GSA/TTS. If you set the
suborg key in override.yml to 18F, 18F branding will be used in the
footer. Other sub-organizations can be added in similar fashion.

Configuration is read in this order, last wins:
- _config.yml
- override.yml
- YAML directly in _data
- YAML in _data/suborgs/[18F, etc.]
- YAML in _data/override

_data/suborgs/18F/usa_anchor.yml

@@ -0,0 +1,5 @@
+site_email: 18F@gsa.gov
+org_secondary: 18F
+org_secondary_logo: 18f-logo-blue.svg
+org_secondary_url: https://18f.gsa.gov
+org_secondary_bio: "18F partners with agencies to improve the user experience of government services by helping them build and buy technology."

_data/usa_anchor.yml

@@ -1,5 +1,4 @@
-site_name: 18F UX Guide
-site_email: 18F@gsa.gov
+site_email: tts-info@gsa.gov
 agency: U.S. General Services Administration
 agency_acronym: GSA
 agency_logo: gsa-logo-blue.svg
@@ -8,10 +7,6 @@ agency_about_url: https://www.gsa.gov/about
 org_primary: Technology Transformation Services
 org_primary_url: https://www.gsa.gov/tts/
 org_primary_bio: "As part of GSA’s Technology Transformation Services (TTS), we apply modern methodologies and technologies to improve the public’s experience with government. We help agencies make their services more accessible, efficient, and effective with modern applications, platforms, processes, personnel, and software solutions."
-org_secondary: 18F
-org_secondary_logo: 18f-logo-blue.svg
-org_secondary_url: https://18f.gsa.gov
-org_secondary_bio: "18F partners with agencies to improve the user experience of government services by helping them build and buy technology."
 foia_request_url: "https://www.gsa.gov/reference/freedom-of-information-act-foia"
 fraud_waste_abuse_url: "https://www.gsaig.gov/"
 no_fear_act_url: "https://www.gsa.gov/about-us/organization/office-of-civil-rights/notification-and-federal-employee-antidiscrimination-and-retaliation-act-of-2002"

_plugins/override.rb

@@ -6,23 +6,29 @@ module Jekyll
   # Loads 18F/uswds-jekyll YAML config files in OVERRIDE_DIR, overriding any keys found in _data.
 
   class OverrideGenerator < Generator
-    OVERRIDE_DIR = '_data/override/'
+    OVERRIDE_DIR = File.join("_data", "override")
+    SUBORGS_DIR = File.join("_data", "suborgs")
 
     safe true
 
     def generate(site)
       yamls = ['header', 'navigation', 'footer', 'theme', 'usa_anchor'] 
       yamls.each do |y|
-        self.merge(site, y)
+        if site.config['suborg']
+          self.merge(site, File.join(SUBORGS_DIR, site.config['suborg']), y)
+        end
+        self.merge(site, OVERRIDE_DIR, y)
       end
       # TODO Address favicons.yml special case
     end
 
-    def merge(site, key)
+    def merge(site, dir, key)
       begin
-        customizations = YAML.load_file(OVERRIDE_DIR + key + '.yml')
+        path = File.join(dir, key + '.yml')
+        customizations = YAML.load_file(path)
         if customizations
           site.data[key].merge!(customizations)
+          puts "        Merged " + path
         end
       rescue
       end

override.yml

@@ -5,6 +5,8 @@
 # - url
 # - github_info
 # - search_site_handle
+# Optional keys
+# - suborg
 
 title: Yet Another TTS Guide
 description: A set of guidelines and best practices
@@ -20,4 +22,5 @@ github_info:
 # usually a good site handle.
 search_site_handle: yet-another-tts-guide
 
-# This should not be merged into instantiatedsite
+# Either 18F or unset
+suborg: 18F