Update issue templates

Added the Algorithm Request template.

Author: aalhour

.github/ISSUE_TEMPLATE/algorithm-request.md

@@ -0,0 +1,26 @@
+---
+name: Algorithm request
+about: Suggest a new algorithm for this project
+title: 'Algorithm request: [NAME]'
+labels: algorithm request
+assignees: ''
+
+---
+
+**Is your algorithm request related to a computational problem? Please describe.**
+A clear and concise description of what the problem is. For example, I am working on the Traveling Sales Man problem, LeetCode problem #123456 and I'd like to ...
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen. For example:
+
+> I'd like to have an algorithm with following interface: [...], where I can define a graph-like map with an visitor iterator function and then ...
+
+Or, more concretely:
+
+> I'd like to have an implementation of this variation of the A* Search Algorithm: [Near Optimal Hierarchical Path-Finding](https://webdocs.cs.ualberta.ca/~mmueller/ps/hpastar.pdf).
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.