Update cheatsheets

ppmtosixel

@@ -0,0 +1,25 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# ppmtosixel
+
+> Convert a PPM image to DEC sixel format.
+> More information: <https://netpbm.sourceforge.net/doc/ppmtosixel.html>.
+
+- Convert a PPM image to DEC sixel format:
+
+`ppmtosixel {{path/to/file.ppm}} > {{path/to/file.sixel}}`
+
+- Produce an uncompressed SIXEL file that is much slower to print:
+
+`ppmtosixel -raw {{path/to/file.ppm}} > {{path/to/file.sixel}}`
+
+- Add a left margin of 1.5 inches:
+
+`ppmtosixel -margin {{path/to/file.ppm}} > {{path/to/file.sixel}}`
+
+- Encode control codes in a more portable (although less space-efficient) way:
+
+`ppmtosixel -7bit {{path/to/file.ppm}} > {{path/to/file.sixel}}`