🐛 Fix documentation for the Config class

The parser that generates the documenation requires the comment for the
documentation to be immediately preceeding the class definition. As part
of the decaffeination process in #16593 a variable declaration was
placed between the class definition and it's documentaiton, causing the
parser to think there was none... and excluding it from the final
result.

Fixes #16955.

src/config.js

@@ -8,6 +8,8 @@ const Color = require('./color')
 const ScopedPropertyStore = require('scoped-property-store')
 const ScopeDescriptor = require('./scope-descriptor')
 
+const schemaEnforcers = {}
+
 // Essential: Used to access all of Atom's configuration details.
 //
 // An instance of this class is always available as the `atom.config` global.
@@ -359,8 +361,6 @@ const ScopeDescriptor = require('./scope-descriptor')
 //
 // * Don't depend on (or write to) configuration keys outside of your keypath.
 //
-const schemaEnforcers = {}
-
 class Config {
   static addSchemaEnforcer (typeName, enforcerFunction) {
     if (schemaEnforcers[typeName] == null) { schemaEnforcers[typeName] = [] }