fix: rebase agent.md

Author: zakahan

docs/docs/agent.md

@@ -129,7 +129,6 @@ root_agent:
     backend: local
   knowledgebase:
     backend: opensearch
-    index: test
   tools:
     - module: demo_tool   # tool 所在的模块
       func: greeting      # tool 的函数名称

docs/docs/installation.md

@@ -70,7 +70,7 @@ model:
   embedding:
     name: doubao-embedding-text-240715
     dim: 2560
-    api_base: https://ark.cn-beijing.volces.com/api/v3/
+    api_base: https://ark.cn-beijing.volces.com/api/v3/embeddings
     api_key:
 
 volcengine: