Add API doc for fact override

Author: Kevin Paulisse

doc/dev/api/v1.md

@@ -33,3 +33,9 @@ The `OctocatalogDiff::API::V1::Catalog` object represents a compiled catalog and
 The `OctocatalogDiff::API::V1::Diff` object represents a difference between two catalogs and supports several methods to get information about the difference.
 
 [Read more about the `OctocatalogDiff::API::V1::Diff` object](/doc/dev/api/v1/objects/diff.md)
+
+#### OctocatalogDiff::API::V1::FactOverride
+
+The `OctocatalogDiff::API::V1::FactOverride` object represents a user-supplied fact that will be used when compiling a catalog.
+
+[Read more about the `OctocatalogDiff::API::V1::FactOverride` object](/doc/dev/api/v1/objects/fact_override.md)

doc/dev/api/v1/objects/fact_override.md

@@ -0,0 +1,24 @@
+# octocatalog-diff v1 API documentation: OctocatalogDiff::API::V1::FactOverride
+
+## Overview
+
+`OctocatalogDiff::API::V1::FactOverride` is an object that represents a user-supplied fact that will be used when compiling a catalog.
+
+## Constructor
+
+#### `#new(<Hash>)`
+
+The hash must contain the following keys:
+
+- `:fact_name` (String) - The name of the fact (e.g. `operatingsystem` or `ipaddress`)
+- `:value` (?) - The value of the fact
+
+## Methods
+
+#### `#fact_name` (String)
+
+Returns the name of the fact as supplied in the constructor.
+
+#### `#value` (?)
+
+Returns the value of the fact as supplied in the constructor.