docs: add docs for the level db adapter and add adapter in install-adapters.sh

Author: yaroslav8765

adapters/install-adapters.sh

@@ -5,7 +5,7 @@ adminforth-facebook-oauth-adapter adminforth-keycloak-oauth-adapter adminforth-m
 adminforth-twitch-oauth-adapter adminforth-image-generation-adapter-openai adminforth-storage-adapter-amazon-s3 \
 adminforth-storage-adapter-local adminforth-image-vision-adapter-openai adminforth-key-value-adapter-ram \
 adminforth-login-captcha-adapter-cloudflare adminforth-login-captcha-adapter-recaptcha adminforth-completion-adapter-google-gemini \
-adminforth-key-value-adapter-redis"
+adminforth-key-value-adapter-redis adminforth-key-value-adapter-leveldb"
 
 # for each
 install_adapter() {

adminforth/documentation/docs/tutorial/05-ListOfAdapters.md

@@ -264,7 +264,26 @@ const adapter = new RedisKeyValueAdapter({
   redisUrl: '127.0.0.1:6379'
 })
 
-adapeter.set('test-key', 'test-value', 120);
+adapeter.set('test-key', 'test-value', 120); //expiry in 120 seconds
+
+```
+
+### LevelDB adapter
+
+```bash
+npm i @adminforth/key-value-adapter-leveldb
+```
+
+LebelDB uses local storage for storing keys.
+
+```ts
+import LevelDBKeyValueAdapter from '@adminforth/key-value-adapter-leveldb'
+
+const adapter = new LevelDBKeyValueAdapter({ 
+  dbPath: './testdb' 
+});
+
+adapeter.set('test-key', 'test-value', 120); //expiry in 120 seconds
 
 ```