docs: add schema instances full_pkg parameter

Signed-off-by: peefy <xpf6677@163.com>

Author: Peefy

docs/reference/lang/spec/schema.md

@@ -816,8 +816,8 @@ Suppose there are schemas a, b, and c, where c inherits b and b inherits a. Sche
 
 Built-in function and members of schema
 
-- instances()
-  Return the list of existing instances of a schema.
+- instances(full_pkg: bool = False)
+  Return the list of existing instances of a schema in the main package. When the `full_pkg` is set `True`, return all schema instances in the whole program.
 
 ### Irrelevant Order Calculation
 

docs/reference/lang/tour.md

@@ -2341,8 +2341,9 @@ Note that the current version of KCL does not yet support user-defined decorator
 
 Built-in functions and members of schema
 
-- instances()
-  Return the list of existing instances of a schema.
+- instances(full_pkg: bool = False)
+  Return the list of existing instances of a schema in the main package. When the `full_pkg` is set `True`, return all schema instances in the whole program.
+
 
 ```python
 schema Person:

i18n/zh-CN/docusaurus-plugin-content-docs/current/reference/lang/spec/schema.md

@@ -816,8 +816,8 @@ Suppose there are schemas a, b, and c, where c inherits b and b inherits a. Sche
 
 Built-in function and members of schema
 
-- instances()
-  Return the list of existing instances of a schema.
+- instances(full_pkg: bool = False)
+  Return the list of existing instances of a schema in the main package. When the `full_pkg` is set `True`, return all schema instances in the whole program.
 
 ### Irrelevant Order Calculation
 

i18n/zh-CN/docusaurus-plugin-content-docs/current/reference/lang/tour.md

@@ -2291,8 +2291,8 @@ schema Person:
 
 内置函数和 schema 成员
 
-- instances（）
-  返回 schema 的现有实例列表。
+- instances(full_pkg: bool = False)
+  返回 schema 的现有实例列表，当 `full_pkg` 设置为 `False` 时，仅返回 main 中的 schema 实例，当 `full_pkg` 设置为 `True` 时，返回整个项目对应 schema 的所有实例。
 
 ```python
 schema Person: