Docs: add exhaustive list of scoped objects

doc/pages/scopes.asciidoc

@@ -2,9 +2,17 @@
 
 == Description
 
-Scopes are groups in which a particular Kakoune object (a variable,
-hook, alias etc) can have different values, depending on the group the
-value was declared in.
+Scopes are groups in which a particular Kakoune object can have different
+values depending on the group the value was declared in.
+
+These scoped objects are:
+
+- aliases (See <<commands#, `:doc commands`>>)
+- faces (See <<faces#, `:doc faces`>>)
+- highlighters (See <<highlighters#, `:doc highlighters`>>)
+- hooks (See <<hooks#, `:doc hooks`>>)
+- keymaps (See <<mapping#, `:doc mapping`>>)
+- options (See <<options#, `:doc options`>>)
 
 == Names and hierarchy
 

src/scope.hh

@@ -32,7 +32,7 @@ public:
     AliasRegistry&       aliases()            { return m_aliases; }
     const AliasRegistry& aliases()      const { return m_aliases; }
     FaceRegistry&        faces()              { return m_faces; }
-    const FaceRegistry&  faces()      const   { return m_faces; }
+    const FaceRegistry&  faces()        const { return m_faces; }
     Highlighters&        highlighters()       { return m_highlighters; }
     const Highlighters&  highlighters() const { return m_highlighters; }
 
@@ -44,7 +44,7 @@ private:
     HookManager   m_hooks;
     KeymapManager m_keymaps;
     AliasRegistry m_aliases;
-    FaceRegistry m_faces;
+    FaceRegistry  m_faces;
     Highlighters  m_highlighters;
 };