Add pull request template (#2942)
Add pull request template (#2942)

Provide contributors with a checklist to ensure quality PRs and to
avoid common pitfalls. The items in the checklist are mostly beyond
the capabilities of automated checker tools and more like reminders
of best practices. Still, they can save lot of valuable reviewer
time (hopefully).

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu
bzsolt/jerryscript,bzsolt/jerryscript,zherczeg/jerryscript,dbatyai/jerryscript,dbatyai/jerryscript,akosthekiss/jerryscript,dbatyai/jerryscript,bzsolt/jerryscript,akosthekiss/jerryscript,robertsipka/jerryscript,zherczeg/jerryscript,akosthekiss/jerryscript,jerryscript-project/jerryscript,zherczeg/jerryscript,akosthekiss/jerryscript,robertsipka/jerryscript,jerryscript-project/jerryscript,akosthekiss/jerryscript,zherczeg/jerryscript,dbatyai/jerryscript,bzsolt/jerryscript,robertsipka/jerryscript,zherczeg/jerryscript,jerryscript-project/jerryscript,robertsipka/jerryscript,robertsipka/jerryscript,jerryscript-project/jerryscript,robertsipka/jerryscript,jerryscript-project/jerryscript,bzsolt/jerryscript,dbatyai/jerryscript