adding install instructions
Squashed 'external/algorithms/' changes from e20e8c2..5b84025

5b84025 Merge branch 'fix_empty_result_astar' into develop_patched
8edf1e3 Always returns start and end nodes when a path is found in astar

git-subtree-dir: external/algorithms
git-subtree-split: 5b84025d80f3abf829cbd5e742ece59ceac2bb19
merge last algorithms commits