docs: update installation instructions in README.md and README.zh_CN.md to specify package name for optional capabilities (#36)

Co-authored-by: minchangwei <minchangwei@tencent.com>

Author: weimch

README.md

@@ -84,7 +84,7 @@ pip install trpc-agent-py
 Install optional capabilities as needed:
 
 ```bash
-pip3 install -e '.[a2a,ag-ui,knowledge,agent-claude,mem0,langfuse]'
+pip3 install -e 'trpc-agent-py[a2a,ag-ui,knowledge,agent-claude,mem0,langfuse]'
 ```
 
 ### Develop Weather Agent

README.zh_CN.md

@@ -84,7 +84,7 @@ pip install trpc-agent-py
 按需安装扩展能力：
 
 ```bash
-pip3 install -e '.[a2a,ag-ui,knowledge,agent-claude,mem0,langfuse]'
+pip3 install -e 'trpc-agent-py[a2a,ag-ui,knowledge,agent-claude,mem0,langfuse]'
 ```