Update cheatsheets

tldr/linux/pkgdiff

@@ -0,0 +1,21 @@
+---
+syntax: markdown
+tags: [tldr, linux]
+source: https://github.com/tldr-pages/tldr.git
+---
+# pkgdiff
+
+> Compare the file contents of two Slackware packages.
+> More information: <https://slackware.nl/slackware/slackware64-current/source/a/pkgtools/manpages/pkgdiff.8>.
+
+- Compare two packages and display differences:
+
+`pkgdiff {{path/to/package1.txz}} {{path/to/package2.txz}}`
+
+- Compare two packages with colorized output:
+
+`pkgdiff -c {{path/to/package1.txz}} {{path/to/package2.txz}}`
+
+- Compare two packages and output a simple unified diff:
+
+`pkgdiff -a {{path/to/package1.txz}} {{path/to/package2.txz}}`