Add initial version of schema specification site

After running the util/generate_docs.py script to parse and extract
the metadata term specifications and their controlled vocabularies,
we use Hugo to generate the HTML site. The HTML site uses Bootstrap
with several ISEAL brand colors gleaned from the corporate website.

site/content/terms/resource-scope-sustainability-issue/index.md

@@ -0,0 +1,9 @@
+---
+title: 'Scope - sustainability issue'
+field: 'is.focus.sustainIssue'
+slug: 'resource-scope-sustainability-issue'
+description: 'The specific sustainability issue(s) covered in the resource - select from control list'
+required: False
+vocabulary: 'resource-scope-sustainability-issue.txt'
+policy: 'Controlled value. Multi select from control list.'
+---

site/content/terms/resource-scope-sustainability-issue/resource-scope-sustainability-issue.txt

@@ -0,0 +1,12 @@
+Child rights and wellbeing
+Climate change
+Consumers and supply chains
+Forests and other ecosystems
+Freshwater and oceans
+Health and wellbeing
+Livelihoods
+Participant costs and benefits
+Pesticides, fertilizers and soil
+Plant and wildlife conservation
+Rights of indigenous peoples and local communities
+Wages and workers' rights