fix: update issue templates for consistency and clarity

.github/pull_request_template.md

@@ -1,23 +1,3 @@
 # Description
 
 <!-- Please include a summary of the change, motivation and context. It it's a but fix, add a reference in format #issue_number -->
-
-# Type of change
-
-<!-- Please put X into brackets of required option OR delete options that are not relevant -->
-
-- [ ] Bug fix
-- [ ] New feature
-- [ ] Refactoring / style
-- [ ] Documentation update / chore
-- [ ] Other (please describe)
-
-# Versioning
-
-<!-- Update the VERSION if you want the PR to be merged. Currently it's a manual 3-steps process:
-  * update VERSION in `versioning.js` using semver principle
-  * for all changed files update hash (the part after `?`) in place where file is requested (usually it's `index.html`)
-  * if the change can be really interesting for end-users, describe it inside the `showUpdateWindow()` function in `versioning.js` -->
-
-- [ ] Version is updated
-- [ ] Changed files hash is updated