docs: improvements to building and docs (#5234)

SECURITY.md

@@ -0,0 +1,26 @@
+# Security Policy
+
+## Supported Versions
+
+Use this section to tell people about which versions of your project are
+currently being supported with security updates.
+
+| Version | Supported          |
+| ------- | ------------------ |
+| 2.x     | :white_check_mark: |
+| < 2.0   | :x:                |
+
+## Reporting a Vulnerability
+
+Vulnerabilities with critical impact should be reported on the [Security](https://github.com/filebrowser/filebrowser/security) page of this repository, which is a private way of communicating vulnerabilities to maintainers. This project is in maintenance-only mode and it can take a while until someone gets back to you.
+
+If it is not a critical vulnerability, please open an issue and we will categorize it as a security issue. By giving visibility, we can get more help from the community at fixing such issues.
+
+When reporting an issue, where possible, please provide at least:
+
+* The commit version the issue was identified at
+* A proof of concept (plaintext; no binaries)
+* Steps to reproduce
+* Your recommended remediation(s), if any.
+
+The File Browser team is a volunteer-only effort, and may reach back out for clarification.