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

tldr/linux/flash

@@ -0,0 +1,29 @@
+---
+syntax: markdown
+tags: [tldr, linux]
+source: https://github.com/tldr-pages/tldr.git
+---
+# flash
+
+> Flash cards in the terminal.
+> More information: <https://github.com/tallguyjenks/fla.sh>.
+
+- Open a menu of available flashcard decks for selection:
+
+`flash`
+
+- Display information about the flashcard system:
+
+`flash -i`
+
+- Change the previewer from default `bat` to `cat`:
+
+`flash -p {{cat}}`
+
+- Display help:
+
+`flash -h`
+
+- Display version:
+
+`flash -v`