Move pages under tldr, lint run.sh, update docs

tldr/linux/poweroff

@@ -0,0 +1,29 @@
+---
+syntax: markdown
+tags: [tldr, linux]
+source: https://github.com/tldr-pages/tldr.git
+---
+# poweroff
+
+> Power off the system.
+> More information: <https://www.man7.org/linux/man-pages/man8/poweroff.8.html>.
+
+- Power off the system:
+
+`poweroff`
+
+- Halt the system (same as `halt`):
+
+`poweroff --halt`
+
+- Reboot the system (same as `reboot`):
+
+`poweroff --reboot`
+
+- Shut down immediately without contacting the system manager:
+
+`poweroff --force --force`
+
+- Write the wtmp shutdown entry without shutting down the system:
+
+`poweroff --wtmp-only`