Update ConfigDB docs for new mix commands

docs/configuration/howto_database_config.md

@@ -124,40 +124,45 @@ The configuration of Pleroma has traditionally been managed with a config file,
 ## Debugging
 
 ### Clearing database config
-You can clear the database config by truncating the `config` table in the database. e.g.,
+You can clear the database config with the following command:
 
-```
-psql -d pleroma_dev
-pleroma_dev=# TRUNCATE config;
-TRUNCATE TABLE
-```
+  **Source:**
+
+  ```
+  $ mix pleroma.config reset
+  ```
+
+  or
+
+  **OTP:**
+
+  ```
+  $ ./bin/pleroma_ctl config reset
+  ```
 
 Additionally, every time you migrate the configuration to the database the config table is automatically truncated to ensure a clean migration.
 
 ### Manually removing a setting
 If you encounter a situation where the server cannot run properly because of an invalid setting in the database and this is preventing you from accessing AdminFE, you can manually remove the offending setting if you know which one it is.
 
-e.g., here is an example showing a minimal configuration in the database. Only the `config :pleroma, :instance` settings are in the table:
+e.g., here is an example showing a the removal of the `config :pleroma, :instance` settings:
 
-```
-$ mix pleroma.config keylist
-The following configuration keys are set in ConfigDB:
+  **Source:**
 
--  instance
+  ```
+  $ mix pleroma.config delete pleroma instance
+  Are you sure you want to continue? [n]  y
+  config :pleroma, :instance deleted from the ConfigDB.
+  ```
 
-```
+  or
 
-```
-$ mix pleroma.config show instance
-config :pleroma, :instance, [name: "MyPleroma", description: "A fun place to hang out!", notify_email: "no-reply@mypleroma.com", email: "admin@mypleroma.com", account_activation_required: true]
+  **OTP:**
 
-```
-
-To delete the saved settings for `:instance`:
-
-```
-$ mix pleroma.config keydel instance
-instance deleted from the ConfigDB.
-```
+  ```
+  $ ./bin/pleroma_ctl config delete pleroma instance
+  Are you sure you want to continue? [n]  y
+  config :pleroma, :instance deleted from the ConfigDB.
+  ```
 
 Now the `config :pleroma, :instance` settings have been removed from the database.