Base: Add a man page for lspci

Author: https://github.com/f-eiwu
Commit: https://github.com/SerenityOS/serenity/commit/7ff256aab6e
Pull-request: https://github.com/SerenityOS/serenity/pull/1251
Reviewed-by: https://github.com/bugaevc

Base/usr/share/man/man8/lspci.md

@@ -0,0 +1,25 @@
+## Name
+
+lspci - list connected PCI devices
+
+## Synopsis
+
+```**sh
+$ lspci
+```
+
+## Description
+
+lspci is a utility for displaying information about PCI buses in the system
+and devices connected to them. It shows a brief list of devices.
+
+## Files
+
+* `/proc/pci` - source of the PCI devices list.
+* `/res/pci.ids` - a database of PCI identifiers used to match available devices to their vendor, device and class names.
+
+## Examples
+
+```sh
+$ lspci
+```