Merge PR#287, Update issue template to remove checkboxes

Author: piksel

.github/ISSUE_TEMPLATE.md

@@ -11,15 +11,7 @@ Tell us what happens instead
 
 ### Version of SharpZipLib
 
-### Obtained from (place an x between the brackets for all that apply)
-- [ ] Compiled from source
- - branch: _______
- - commit: _______
-- [ ] Downloaded DLL from GitHub
-- [ ] Downloaded DLL from SourceForge
-- [ ] Downloaded DLL from _______
-- [ ] DLL included as part of
-- Package installed using:
- - [ ] NuGet
- - [ ] MyGet
- - [ ] Chocolatey
+### Obtained from (only keep the relevant lines)
+- Compiled from source, commit: _______
+- Downloaded from GitHub
+- Package installed using NuGet