Remove links to source code and make examples generic in migrating - attributes & blocks - default values (#418)

Author: bendbennett

website/docs/plugin/framework/migrating/attributes-blocks/default-values.mdx

@@ -61,24 +61,16 @@ In the Framework, you must implement an attribute plan modifier to set default v
 
 ## Example
 
-The following examples show how to migrate portions of the [tls](https://github.com/hashicorp/terraform-provider-tls)
-provider.
-
-For a complete example, clone the
-`terraform-provider-tls` repository and compare the `resource_private_key.go` file in
-[v3.4.0](https://github.com/hashicorp/terraform-provider-tls/blob/v3.4.0/internal/provider/resource_private_key.go) with the file
-[after the migration](https://github.com/hashicorp/terraform-provider-tls/blob/4dafb105818e45a88532f917e7b170ee2a9bb092/internal/provider/resource_private_key.go).
-
 ### SDKv2
 
-The following example from the `resource_private_key.go` file shows the implementation of the `Default` field for the
-`rsa_bits` attribute on the `tls_private_key` resource with SDKv2.
+The following example shows the implementation of the `Default` field for the
+`example_attribute` attribute on the `exampleResource` resource with SDKv2.
 
 ```go
-func resourcePrivateKey() *schema.Resource {
+func exampleResource() *schema.Resource {
     return &schema.Resource{
         Schema: map[string]*schema.Schema{
-            "rsa_bits": {
+            "example_attribute": {
                 Default:     2048,
                 /* ... */
             },
@@ -89,13 +81,13 @@ func resourcePrivateKey() *schema.Resource {
 
 The following shows the same section of code after the migration.
 
-This code implements the `PlanModifiers` field for the `rsa_bits` attribute with the Framework.
+This code implements the `PlanModifiers` field for the `example_attribute` attribute with the Framework.
 
 ```go
-func (r *privateKeyResource) Schema(ctx context.Context, req resource.SchemaRequest, resp *resource.SchemaResponse) {
+func (r *exampleResource) Schema(ctx context.Context, req resource.SchemaRequest, resp *resource.SchemaResponse) {
     resp.Schema = schema.Schema{
         Attributes: map[string]schema.Attribute{
-            "rsa_bits": schema.Int64Attribute{
+            "example_attribute": schema.Int64Attribute{
                 PlanModifiers: []planmodifier.Int64{
                     attribute_plan_modifier.Int64DefaultValue(types.Int64Value(2048)),
                     /* ... */
@@ -108,8 +100,8 @@ func (r *privateKeyResource) Schema(ctx context.Context, req resource.SchemaRequ
 }
 ```
 
-The following example from the `attribute_plan_modifiers.go` file implements the `DefaultValue` attribute plan modifier
-that the `rsa_bits` attribute uses.
+The following example implements the `Int64DefaultValue` attribute plan modifier
+that the `example_attribute` attribute uses.
 
 ```go
 func Int64DefaultValue(v types.Int64) planmodifier.Int64 {