Add key-value table

doc/database.md

@@ -40,6 +40,7 @@ Database Tables
 | [inbox-status](help/database/db_inbox-status) | Status of ActivityPub inboxes |
 | [intro](help/database/db_intro) |  |
 | [item-uri](help/database/db_item-uri) | URI and GUID for items |
+| [key-value](help/database/db_key-value) | A key value storage |
 | [locks](help/database/db_locks) |  |
 | [mail](help/database/db_mail) | private messages |
 | [mailacct](help/database/db_mailacct) | Mail account data for fetching mails |

doc/database/db_key-value.md

@@ -0,0 +1,24 @@
+Table key-value
+===========
+
+A key value storage
+
+Fields
+------
+
+| Field | Description | Type          | Null | Key | Default | Extra          |
+| ----- | ----------- | ------------- | ---- | --- | ------- | -------------- |
+| id    |             | int unsigned  | NO   | PRI | NULL    | auto_increment |
+| k     |             | varbinary(50) | NO   |     |         |                |
+| v     |             | mediumtext    | YES  |     | NULL    |                |
+
+Indexes
+------------
+
+| Name    | Fields    |
+| ------- | --------- |
+| PRIMARY | id        |
+| k       | UNIQUE, k |
+
+
+Return to [database documentation](help/database)