doc: add schema annotation to entgo.io (#880)

doc/md/schema-annotations.md

@@ -0,0 +1,45 @@
+---
+id: schema-annotations
+title: Annotations
+---
+
+Schema annotations allow attaching metadata to schema objects like fields and edges and inject them to external templates.
+An annotation must be a Go type that is serializable to JSON raw value (e.g. struct, map or slice)
+and implement the [Annotation](https://pkg.go.dev/github.com/facebook/ent/schema/field?tab=doc#Annotation) interface.
+
+The builtin annotations allow configuring the different storage drivers (like SQL) and control the code generation output. 
+
+## Custom Table Name
+
+A custom table name can be provided for types using the `entsql` annotation as follows:
+
+```go
+package schema
+
+import (
+	"github.com/facebook/ent"
+	"github.com/facebook/ent/dialect/entsql"
+	"github.com/facebook/ent/schema"
+	"github.com/facebook/ent/schema/field"
+)
+
+// User holds the schema definition for the User entity.
+type User struct {
+	ent.Schema
+}
+
+// Annotations of the User.
+func (User) Annotations() []schema.Annotation {
+	return []schema.Annotation{
+		entsql.Annotation{Table: "Users"},
+	}
+}
+
+// Fields of the User.
+func (User) Fields() []ent.Field {
+	return []ent.Field{
+		field.Int("age"),
+		field.String("name"),
+	}
+}
+```  

doc/md/schema-config.md

@@ -1,34 +0,0 @@
----
-id: schema-config
-title: Config
----
-
-## Custom Table Name
-
-A custom table name can be provided for types using the `Table` option as follows:
-
-```go
-package schema
-
-import (
-	"github.com/facebook/ent"
-	"github.com/facebook/ent/schema/field"
-)
-
-type User struct {
-	ent.Schema
-}
-
-func (User) Config() ent.Config {
-	return ent.Config{
-		Table: "Users",
-	}
-}
-
-func (User) Fields() []ent.Field {
-	return []ent.Field{
-		field.Int("age"),
-		field.String("name"),
-	}
-}
-```  

doc/md/templates.md

@@ -69,7 +69,7 @@ In order to override an existing template, use its name. For example:
 ```
 
 ## Annotations
-Schema annotations allow to attach metadata to fields and edges and inject them to external templates.  
+Schema annotations allow attaching metadata to fields and edges and inject them to external templates.  
 An annotation must be a Go type that is serializable to JSON raw value (e.g. struct, map or slice)
 and implement the [Annotation](https://pkg.go.dev/github.com/facebook/ent/schema/field?tab=doc#Annotation) interface.
 

doc/website/sidebars.json

@@ -8,8 +8,8 @@
       "schema-fields",
       "schema-edges",
       "schema-indexes",
-      "schema-config",
-      "schema-mixin"
+      "schema-mixin",
+      "schema-annotations"
     ],
     "Code Generation": [
       "code-gen",