Correcting X-XSS-Protection Header (#136)

* Correcting X-XSS-Protection Header

X-XSS-Protection sets the configuration for the cross-site scripting filters built into most browsers. The best configuration is "X-XSS-Protection: 1; mode=block".

Was "0"
Now "1; mode=block"

* Update issue templates

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,36 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: bug
+assignees: ''
+
+---
+
+**Checklist**
+- Have you pulled and found the error with `jc21/nginx-proxy-manager:latest` docker image?
+- Are you sure you're not using someone else's docker image?
+- If having problems with Lets Encrypt, have you made absolutely sure your site is accessible from outside of your network?
+
+**Describe the bug**
+- A clear and concise description of what the bug is.
+- What version of Nginx Proxy Manager is reported on the login page?
+
+**To Reproduce**
+Steps to reproduce the behavior:
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Operating System**
+- Please specify if using a Rpi, Mac, orchestration tool or any other setups that might affect the reproduction of this error.
+
+**Additional context**
+Add any other context about the problem here, docker version, browser version if applicable to the problem. Too much info is better than too little.