Add KeepassXC

KeepassX is no longer maintained, and maybe should be removed. But KeePassXC is still maintained.

README.md

@@ -589,6 +589,7 @@ firewall zones to define the trust level of network connections or interfaces. !
 - [indicator-multiload](https://launchpad.net/ubuntu/+source/indicator-multiload) - Graphical system load indicator for CPU, ram, etc. ![Freeware][Freeware Icon]
 - [Indicator-SysMonitor](https://github.com/fossfreedom/indicator-sysmonitor) - An Application Indicator showing cpu temperature, memory, network speed, cpu usage, public IP address and internet connection status. [![Open-Source Software][OSS Icon]](https://github.com/fossfreedom/indicator-sysmonitor) ![Freeware][Freeware Icon]
 - [KeePassX](https://www.keepassx.org/) - Cross platform password manager. Port of KeePass. [![Open-Source Software][OSS Icon]](https://github.com/keepassx/keepassx) ![Freeware][Freeware Icon]
+- [KeePassXC](https://keepassxc.org/) - Cross platform password manager. A Community-maintained fork of KeePassX [![Open-Source Software][OSS Icon]](https://github.com/keepassxreboot/keepassxc) ![Freeware][Freeware Icon]
 - [KeePass](https://www.keepass.info/) - Windows focused password manager, with some cross platform support through Mono.  ![Freeware][Freeware Icon]
 - [KVM](http://www.linux-kvm.org/page/Main_Page) - KVM (for Kernel-based Virtual Machine) is a full virtualization solution for Linux on x86 hardware containing virtualization extensions (Intel VT or AMD-V). [![Open-Source Software][OSS Icon]](https://sourceforge.net/projects/kvm/files/) ![Freeware][Freeware Icon]
 - [LastPass](https://lastpass.com/misc_download2.php) - Cross platform password <manager class="" Freeware="" Icon=""></manager>