Add file SECURITY.md (#40)

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* Add default SECURITY.md file

Co-authored-by: ld-repository-standards[bot] <113625520+ld-repository-standards[bot]@users.noreply.github.com>

SECURITY.md

@@ -1,4 +1,4 @@
-#Reporting and Fixing Security Issues
+# Reporting and Fixing Security Issues
 
 Please report all security issues to the LaunchDarkly security team by submitting a bug bounty report to our [HackerOne program](https://hackerone.com/launchdarkly?type=team). LaunchDarkly will triage and address all valid security issues following the response targets defined in our program policy. Valid security issues may be eligible for a bounty.