Update INSTALLATION.md

[wq2625]

LXCFS is a simple userspace filesystem designed to work around some current limitations of the Linux kernel.
So we modify 'lxcfs' to 'LXCFS' to avoid confusion.

[pouchrobot]

@wq2526 Thanks for your contribution. 🍻
Please sign off in each of your commits.

[pouchrobot]

We found this is your first time to contribute to Pouch, @wq2526
👏 We really appreciate it.
Just remind that you have read the contribution guide: https://github.com/alibaba/pouch/blob/master/CONTRIBUTING.md
If you didn't, you should do that first. If done, welcome again and please enjoy hacking! 🍻

[CLAassistant]

All committers have signed the CLA.

[codecov-io]

Codecov Report

Merging #1698 into master will decrease coverage by 23.02%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           master    #1698       +/-   ##
===========================================
- Coverage   41.16%   18.13%   -23.03%     
===========================================
  Files         274      228       -46     
  Lines       18091    15271     -2820     
===========================================
- Hits         7447     2770     -4677     
- Misses       9729    12307     +2578     
+ Partials      915      194      -721

Impacted Files	Coverage Δ
pkg/httputils/http_utils.go	0% <0%> (-100%)	⬇️
pkg/httputils/http_error.go	0% <0%> (-100%)	⬇️
apis/server/router.go	0% <0%> (-91.37%)	⬇️
daemon/mgr/container_state.go	0% <0%> (-87.24%)	⬇️
apis/server/volume_bridge.go	0% <0%> (-86.67%)	⬇️
daemon/containerio/hijack_conn.go	2.85% <0%> (-85.72%)	⬇️
daemon/mgr/container_monitor.go	0% <0%> (-85.19%)	⬇️
daemon/mgr/container_logger.go	0% <0%> (-84%)	⬇️
daemon/mgr/spec_annotations.go	0% <0%> (-82.36%)	⬇️
apis/server/container_bridge.go	0% <0%> (-82.02%)	⬇️
... and 130 more

---

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[allencloud]

LGTM