Add RFP issue template

Author: semuelle

.github/ISSUE_TEMPLATE/request-for-proposal.md

@@ -0,0 +1,47 @@
+---
+name: Request for Proposal
+about: Suggest a project idea that should be funded by the Grants Program
+title: "[RFP] "
+labels: rfp
+assignees: ''
+
+---
+
+* **Status:** **Open** (anyone is allowed to apply) / **Closed** (invited respondents only)
+* **Projects you think this work could be useful for** [optional]: Link(s)
+
+## Project Description
+
+Please describe exactly why you are proposing this RFP. Make sure to point out why it’s needed and/or useful for your project or other projects in the ecosystem.  
+
+## Deliverables
+
+Please list potential deliverables of the project in as much detail as possible, but keep in mind that this roadmap is not binding and that applications might deviate from it.
+
+Please also estimate the amount of work required and try to divide the project into meaningful milestones.
+
+* **Total Estimated Duration:**    Expected duration of the whole project
+* **Full-time equivalent (FTE):** Expected number of full-time employees working on the project throughout its duration ([see](https://en.wikipedia.org/wiki/Full-time_equivalent)) 
+* **Total Costs:**                         Expected amount required, in USD, for the whole project. 
+
+### Milestone 1
+
+* **Estimated Duration:** Expected duration of Milestone 1 
+* **FTE:**                         Expected number of full-time employees working on this milestone
+* **Costs:**                      Expected amount required, in USD, for Milestone 1
+
+
+| Number | Deliverable | Specification | 
+| ----------- | --------------- | ----------------- |
+| 1.           | Title of the deliverable | Please describe the deliverable here as detailed as possible |  
+| 2.           | ... | ... | 
+
+
+### Milestone 2
+
+...
+
+---
+
+* **Proposer:** Your GitHub username
+* **Your Project(s):** [optional]: Link(s)