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

tldr/pio

@@ -0,0 +1,22 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# pio
+
+> Development environment for embedded boards.
+> Some subcommands such as `pio run` have their own usage documentation.
+> More information: <https://docs.platformio.org/en/latest/core/userguide/>.
+
+- Display help and list subcommands:
+
+`pio --help`
+
+- Display help for a specific subcommand:
+
+`pio {{subcommand}} --help`
+
+- Display version:
+
+`pio --version`