add doc (#145)

add doc explain how to map multiple yaml files to one plugin
implementation.

website/docs/customization/plugin/multi_yaml_single_impl.md

@@ -0,0 +1,79 @@
+---
+id: multi_yaml_single_impl
+description: Multiple YAML files to one Python implementation
+slug: /plugin/multi_yaml_single_impl
+---
+
+# Multiple YAML files to one Python implementation
+
+In practice, you may want to have multiple plugins that share the same implementation.
+For example, you may want to have two plugins that both pull data from a database, but one pulls data from database A and the other pulls data from database B.
+In this case, the plugin implementation code is the same, but the plugin configuration is different.
+It would be cumbersome to copy and paste the same implementation code to two different files.
+
+To solve this problem, TaskWeaver allows you to have multiple plugin configurations that share the same implementation.
+Here is an example of the plugin configuration for the two plugins that pull data from database A and B respectively:
+
+The configuration for the plugin that pulls data from database A:
+```yaml
+name: sql_pull_data_from_A
+code: sql_pull_data
+...
+description: >-
+  Pull data from a SQL database A. The database A contains information about merchandise sales.
+examples: |-
+  df, description = sql_pull_data_from_A("pull data from time_series table")
+parameters:
+  ...
+returns:
+  ...
+configurations:
+  ...
+  sqlite_db_path: /path/to/sqlite_A.db
+```
+
+The configuration for the plugin that pulls data from database B:
+```yaml
+name: sql_pull_data_from_B
+code: sql_pull_data
+...
+description: >-
+  Pull data from a SQL database B. The database B contains information about customer information.
+examples: |-
+  df, description = sql_pull_data_from_B("pull data from time_series table")
+parameters:
+  ...
+returns:
+  ...
+configurations:
+  ...
+  sqlite_db_path: /path/to/sqlite_B.db
+```
+
+Let's discuss the differences between the two configurations. 
+
+First, you can see that the `name` field is different, and the names are different from the python file name (without extension) which is `sql_pull_data.py`.
+This name is used in CodeInterpreter for code generation. So, you can see that in the `examples` field, 
+the function name is `sql_pull_data_from_A` and `sql_pull_data_from_B`, respectively.
+
+Second, you can see that the `code` field is the same, and the code file name is `sql_pull_data.py`.
+This means that the two plugins share the same implementation code. 
+The `code` field is optional, and if you don't specify it, the plugin name will be used as the code file name without the extension.
+
+Third, you can see that the `configurations` field is different, and the `sqlite_db_path` is different.
+This means that the two plugins have different configurations.
+This is typically the key reason why you want to have multiple plugin configurations that share the same implementation.
+
+Finally, you can see that the `description` field is different, and the descriptions are different.
+This is important because the Planner and the CodeInterpreter will use the description to make decisions and generate code.
+The two descriptions should be explicit enough to distinguish the two plugins. 
+Otherwise, the Planner and the CodeInterpreter may not be able to make the right decisions.
+
+## Conclusion
+When you meet the situation where you want to have multiple plugin configurations that share the same implementation,
+you can use the `code` field to specify the code file name, and use the `configurations` field to specify the configurations.
+The `name` field is used to distinguish the plugins, and the `description` field is used to 
+help the Planner and the CodeInterpreter make right decisions.
+
+
+

website/sidebars.js

@@ -60,7 +60,7 @@ const sidebars = {
         label: 'Plugin',
         collapsible: true,
         collapsed: true,
-        items: ['customization/plugin/plugin_intro', 'customization/plugin/plugin_selection', 'customization/plugin/embedding', 'customization/plugin/develop_plugin'],
+        items: ['customization/plugin/plugin_intro', 'customization/plugin/plugin_selection', 'customization/plugin/embedding', 'customization/plugin/develop_plugin', 'customization/plugin/multi_yaml_single_impl'],
       },
       {
         type: 'category',