Consolidate documentation (#3071)

* 🔥 consolidate documentation
* ♻️ overwork std specializations
* 🚚 move images files to mkdocs
* ♻️ fix URLs
* 🔧 tweak MkDocs configuration
* 🔧 add namespaces
* 📝 document deprecations
* 📝 document documentation generation
* 🚸 improve search
* 🚸 add examples
* 🚧 start adding documentation for macros
* 📝 add note for https://github.com/nlohmann/json/issues/874#issuecomment-1001699139
* 📝 overwork example handling
* 📝 fix Markdown tables

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

@@ -1,4 +1,4 @@
-# basic_json::diff
+# <small>nlohmann::basic_json::</small>diff
 
 ```cpp
 static basic_json diff(const basic_json& source,
@@ -33,11 +33,11 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
 
 Linear in the lengths of `source` and `target`.
 
-## Note
+## Notes
 
 Currently, only `remove`, `add`, and `replace` operations are generated.
           
-## Example
+## Examples
 
 ??? example
 
@@ -53,6 +53,10 @@ Currently, only `remove`, `add`, and `replace` operations are generated.
     --8<-- "examples/diff.output"
     ```
 
+## See also
+
+- [RFC 6902 (JSON Patch)](https://tools.ietf.org/html/rfc6902)
+
 ## Version history
 
 - Added in version 2.0.0.