docs: supported versions & security policy

Author: morremeyer

README.md

@@ -5,6 +5,12 @@ Envelope Zero is fundamentally rooted in two ideas:
 - Using the [envelope method](https://en.wikipedia.org/wiki/Envelope_system) to budget expenses into envelopes.
 - Zero Based Budeting, meaning that you assign all your money to an envelope. Saving for a vacation? Create an envelope and archive it after your vacation. Rent? Create an envelope that gets a fixed amount of money added every month.
 
+## Supported Versions
+
+This project is under heavy development. Therefore, only the latest release is supported.
+
+Please check the [releases page](https://github.com/envelope-zero/backend/releases) for the latest release.
+
 ## Contributing
 
 Please see [the contribution guidelines](CONTRIBUTING.md).

SECURITY.md

@@ -0,0 +1,9 @@
+# Security Policy
+
+## Reporting a Vulnerability
+
+Please do not open an issue if you find a vulnerability. Send an email to [email protected] and a maintainer will get in touch with you as soon as possible. This might take up to 72 hours.
+
+You will be kept up to date with all developments via email.
+
+Once your report has been checked and the vulnerability is confirmed, it will be patched as soon as possible and issue a security advisory will be released with the patch.