feat(haproxy): add k3s haproxy lb config snippet

# HAProxy snippets

## HAProxy Load Balancer for k3s

This guide assumes you have a HAProxy load balancer setup to proxy traffic to your k3s cluster nodes. The load balancer

will distribute incoming requests to the k3s API server across multiple master nodes, ensuring high availability.

```bash

global

    log /dev/log local0

    log /dev/log local1 notice

    chroot /var/lib/haproxy

    stats socket /run/haproxy/admin.sock mode 660 level admin

    stats timeout 30s

    user haproxy

    group haproxy

    daemon

defaults

    log     global

    mode    tcp

    option  tcplog

    option  dontlognull

    timeout connect 5000

    timeout client  50000

    timeout server  50000

frontend k3s-http

    bind 192.168.10.230:80

    default_backend k3s-http

frontend k3s-https

    bind 192.168.10.230:443

    default_backend k3s-https

frontend k3s-api

    bind 192.168.10.230:6443

    default_backend k3s-nodes

backend k3s-http

    balance roundrobin

    stick-table type ip size 200k expire 30m

    stick on src

    option tcp-check

    server node01 192.168.10.231:80 check

    server node02 192.168.10.232:80 check

    server node03 192.168.10.233:80 check

backend k3s-https

    balance roundrobin

    stick-table type ip size 200k expire 30m

    stick on src

    option tcp-check

    server node01 192.168.10.231:443 check

    server node02 192.168.10.232:443 check

    server node03 192.168.10.233:443 check

backend k3s-nodes

    balance roundrobin

    option tcp-check

    server node01 192.168.10.231:6443 check

    server node02 192.168.10.232:6443 check

    server node03 192.168.10.233:6443 check

```