doc: update documentation to include naming convention (#1144)

* Update documentation to include naming convention

This change relates to my question in #1107 around naming convention for fields / edges. As a bonus, I added documentation around the StructTag method for edges, as seemed to be omitted.

* s/camel/Pascal/g

doc/md/schema-edges.md

@@ -898,6 +898,23 @@ func (User) Edges() []ent.Edge {
 }
 ```
 
+## Struct Tags
+
+Custom struct tags can be added to the generated entities using the `StructTag`
+method. Note that if this option was not provided, or provided and did not
+contain the `json` tag, the default `json` tag will be added with the field name.
+
+```go
+// Edges of the User.
+func (User) Edges() []ent.Edge {
+	return []ent.Edge{
+		edge.To("pets", Pet.Type).
+			// Override the default json tag "pets" with "owner" for O2M relationship.
+			StructTag(`json:"owner"`),
+	}
+}
+```
+
 ## Indexes
 
 Indexes can be defined on multi fields and some types of edges as well.
@@ -932,3 +949,8 @@ func (Pet) Edges() []ent.Edge {
 ```
 
 Read more about annotations and their usage in templates in the [template doc](templates.md#annotations).
+
+## Naming Convention
+
+By convention edge names should use `snake_case`. The corresponding struct fields generated by `ent` will follow the Go convention
+of using `PascalCase`. In cases where `PascalCase` is desired, you can do so with the `StorageKey` or `StructTag` methods.

doc/md/schema-fields.md

@@ -554,3 +554,8 @@ func (User) Fields() []ent.Field {
 ```
 
 Read more about annotations and their usage in templates in the [template doc](templates.md#annotations).
+
+## Naming Convention
+
+By convention field names should use `snake_case`. The corresponding struct fields generated by `ent` will follow the Go convention
+of using `PascalCase`. In cases where `PascalCase` is desired, you can do so with the `StorageKey` or `StructTag` methods.