Start perparation for kotlin/native merge into kotlin repo

This is first commit that should't be in kotlin/native master
and should be done only in kotlin repo.
Removed .gitmodule -- because it wasn't used.
.github/* -- because in kotlin repo issues are disabled
.idea/vcs.xml -- because kotlin already has this settings

.github/ISSUE_TEMPLATE/config.yml

@@ -1 +0,0 @@
-blank_issues_enabled: false

.github/ISSUE_TEMPLATE/please-use-youtrack.md

@@ -1,26 +0,0 @@
----
-name: Please use YouTrack for bugs and feature requests
-about: "Proceed to get more details"
-title: Please read the text below
-labels: 'from-template'
-assignees: 'artdfel'
-
----
-
-Please read the text below.
-
-# Are you reporting a bug or requesting a feature?
-
-Please don't submit GitHub issue, create YouTrack issue instead: https://kotl.in/issue
-
-# Are you asking a question?
-
-Please use StackOverflow with `kotlin-native` tag: https://stackoverflow.com/questions/ask?tags=kotlin-native
-
-Also feel free to ask or discuss anything on `#kotlin-native` and `#multiplatform` channels in Slack workspace for Kotlin community -- https://slack.kotl.in.
-
-# Not sure?
-
-Then you are probably asking a question, see above.
-
-Please avoid creating new GitHub issues in any case. More details: https://github.com/JetBrains/kotlin-native/issues/4079

.idea/vcs.xml

@@ -1,20 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="IssueNavigationConfiguration">
-    <option name="links">
-      <list>
-        <IssueNavigationLink>
-          <option name="issueRegexp" value="((KT|KTI|IDEA)\-(\d+))" />
-          <option name="linkRegexp" value="https://youtrack.jetbrains.com/issue/$1" />
-        </IssueNavigationLink>
-        <IssueNavigationLink>
-          <option name="issueRegexp" value="#(\d+)" />
-          <option name="linkRegexp" value="https://github.com/JetBrains/kotlin-native/issues/$1" />
-        </IssueNavigationLink>
-      </list>
-    </option>
-  </component>
-  <component name="VcsDirectoryMappings">
-    <mapping directory="" vcs="Git" />
-  </component>
-</project>