Add a bunch of new documentation to completions

crates/ra_hir/src/code_model_api.rs

@@ -394,6 +394,12 @@ impl Const {
     }
 }
 
+impl Docs for Const {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        docs_from_ast(&*self.source(db).1)
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Static {
     pub(crate) def_id: DefId,
@@ -409,6 +415,12 @@ impl Static {
     }
 }
 
+impl Docs for Static {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        docs_from_ast(&*self.source(db).1)
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Trait {
     pub(crate) def_id: DefId,
@@ -428,6 +440,12 @@ impl Trait {
     }
 }
 
+impl Docs for Trait {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        docs_from_ast(&*self.source(db).1)
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Type {
     pub(crate) def_id: DefId,
@@ -446,3 +464,9 @@ impl Type {
         db.generic_params(self.def_id)
     }
 }
+
+impl Docs for Type {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        docs_from_ast(&*self.source(db).1)
+    }
+}