Update issue templates (#284)

* Update issue templates

* Create package.md

.github/ISSUE_TEMPLATE/language-request.md

@@ -0,0 +1,10 @@
+---
+name: Language Request
+about: Template for requesting language support
+title: Add [insert language name here]
+labels: package
+assignees: ''
+
+---
+
+Provide links to different compilers/interpreters that could be used to implement this language, and discuss pros/cons of each.

.github/PULL_REQUEST_TEMPLATE/package.md

@@ -0,0 +1,10 @@
+Checklist:
+* [ ] The package builds locally with `./piston build-pkg [package] [version]`
+* [ ] The package installs with `./piston ppman install [package]=[version]`
+* [ ] The package runs the test code with `./piston run [package] -l [version] packages/[package]/[version]/test.*`
+* [ ] Package files are placed in the correct directory
+* [ ] No old package versions are removed
+* [ ] All source files are deleted in the `build.sh` script
+* [ ] `metadata.json`'s `language` and `version` fields match the directory path
+* [ ] Any extensions the language may use are set as aliases
+* [ ] Any alternative names the language is referred to are set as aliases.