[DOCS] Document Depth First Search (DFS)

[bobluppes]

Documentation Depth First Search (DFS)

The goal of this issue if the improve the documentation of an existing algorithm. This documentation should go into the algorithms section of our docusaurus docs.

More detail on how to build the documentation locally can be found on the wiki.

An existing documentation page exists, which should be extended. The page can be found under docs/docs/algorithms/traversal/depth-first-search.md.

The corresponding algorithm is called depth_first_traverse and can be found under include/graaflib/algorithm/graph_traversal.h.

Documentation Contents

The documentation entry should adhere to the following template:

# [ALGORITHM_NAME]
- A short description of the algorithm, what does it do and in which use cases is it used.
- What are the limitations of the algorithm, does it work on both directed and undirected graphs? Does it consider edge weights, and if yes, does it support negative weights?
- Link to the wikipedia entry on the algorithm.

## Syntax
- A code block with the syntax of the algorithm. This should now include any javadoc comments.
- An explanation of the parameters (including template parameters) and the return type.

## (Optional) See also
- If there are similar algorithms, or we have a slightly different version of the same algorithm, you can link it here.
- If we have an example (found on the example page of the docs) which uses this algorithm, you can link it here.