📝 add more API documentation

doc/mkdocs/docs/api/basic_json/index.md

@@ -194,9 +194,9 @@ Access to the JSON value
 - [**operator==**](operator==.md) - comparison: equal
 - [**operator!=**](operator!=.md) - comparison: not equal
 - [**operator<**](operator<.md) - comparison: less than
-- operator<= - comparison: less than or equal
+- [**operator<=**](operator<=.md) - comparison: less than or equal
 - [**operator>**](operator>.md) - comparison: greater than
-- operator>= - comparison: greater than or equal
+- [**operator>=**](operator>=.md) - comparison: greater than or equal
 
 ### Serialization
 

doc/mkdocs/docs/api/basic_json/operator<=.md

@@ -0,0 +1,59 @@
+# basic_json::operator<=
+
+```cpp
+bool operator<=(const_reference lhs, const_reference rhs) noexcept,
+
+template<typename ScalarType>
+bool operator<=(const_reference lhs, const ScalarType rhs) noexcept;
+
+template<typename ScalarType>
+bool operator<=(ScalarType lhs, const const_reference rhs) noexcept;
+```
+
+Compares whether one JSON value `lhs` is less than or equal to another JSON value `rhs` by calculating
+`#cpp !(rhs < lhs)`.
+
+## Template parameters
+
+`ScalarType`
+:   a scalar type according to `std::is_scalar<ScalarType>::value`
+
+## Parameters
+
+`lhs` (in)
+:   first value to consider 
+
+`rhs` (in)
+:   second value to consider 
+
+## Return value
+
+whether `lhs` is less than or equal to `rhs`
+
+## Exception safety
+
+No-throw guarantee: this function never throws exceptions.
+
+## Complexity
+
+Linear.
+
+## Example
+
+??? example
+
+    The example demonstrates comparing several JSON types.
+        
+    ```cpp
+    --8<-- "examples/operator__lessequal.cpp"
+    ```
+    
+    Output:
+    
+    ```json
+    --8<-- "examples/operator__lessequal.output"
+    ```
+
+## Version history
+
+- Added in version 1.0.0.

doc/mkdocs/docs/api/basic_json/operator>=.md

@@ -0,0 +1,59 @@
+# basic_json::operator>=
+
+```cpp
+bool operator>=(const_reference lhs, const_reference rhs) noexcept,
+
+template<typename ScalarType>
+bool operator>=(const_reference lhs, const ScalarType rhs) noexcept;
+
+template<typename ScalarType>
+bool operator>=(ScalarType lhs, const const_reference rhs) noexcept;
+```
+
+Compares whether one JSON value `lhs` is greater than or equal to another JSON value `rhs` by calculating
+`#!cpp !(lhs < rhs)`.
+
+## Template parameters
+
+`ScalarType`
+:   a scalar type according to `std::is_scalar<ScalarType>::value`
+
+## Parameters
+
+`lhs` (in)
+:   first value to consider 
+
+`rhs` (in)
+:   second value to consider 
+
+## Return value
+
+whether `lhs` is less than or equal to `rhs`
+
+## Exception safety
+
+No-throw guarantee: this function never throws exceptions.
+
+## Complexity
+
+Linear.
+
+## Example
+
+??? example
+
+    The example demonstrates comparing several JSON types.
+        
+    ```cpp
+    --8<-- "examples/operator__greaterequal.cpp"
+    ```
+    
+    Output:
+    
+    ```json
+    --8<-- "examples/operator__greaterequal.output"
+    ```
+
+## Version history
+
+- Added in version 1.0.0.