Documentation updated, library working from C++11 to C++23

What's Changed

• Update by @Terae in #4

Full Changelog: v1.1.2...v1.2.1

Graph library with common search algorithms, v1.1.2

• Restructuration of search algorithms
  • better usage of common algorithms
  • implementation of Dijkstra's algorithm
• Serialization to/from JSON, to DOT, to/from own text representation

Graph library with common search algorithms, v1.1.1

Merge from dev, version 1.1.1

Graph library with common search algorithms, v1.1.0

Changing version to v1.1.0: Search algorithms implemented.

Functional graph library version 1.0.1

v1.0.1

Fix a problem into the test suite.