More documentation updates for 3.11.0 (#3553)

* mkdocs: add string_view examples

* mkdocs: reference underlying operators

* mkdocs: add operator<=> examples

* mkdocs: fix style check issues

* mkdocs: tweak BJData page

* mkdocs: add CMake option hints to macros

* mkdocs: fix JSON_DISABLE_ENUM_SERIALIZATION definition

* mkdocs: fix link to unit-udt.cpp

* mkdocs: fix "Arbitrary Type Conversions" title

* mkdocs: link to api/macros/*.md instead of features/macros.md

* mkdocs: document JSON_DisableEnumSerialization CMake option

* mkdocs: encode required C++ standard in example files

* docset: detect gsed/sed

* docset: update index

* docset: fix CSS patching

* docset: add list_missing_pages make target

* docset: add list_removed_paths make target

* docset: replace page titles with name from index

* docset: add install target for Zeal docset browser

* Use GCC_TOOL in ci_test_documentation target

docs/mkdocs/docs/api/macros/json_has_ranges.md

@@ -13,6 +13,19 @@ The default value is detected based on the preprocessor macro `#!cpp __cpp_lib_r
 
 When the macro is not defined, the library will define it to its default value.
 
+## Examples
+
+??? example
+
+    The code below forces the library to enable support for ranges:
+
+    ```cpp
+    #define JSON_HAS_RANGES 1
+    #include <nlohmann/json.hpp>
+
+    ...
+    ```
+
 ## Version history
 
 - Added in version 3.11.0.