pup: add page (tldr-pages#1533)

pages/common/pup.md

@@ -0,0 +1,27 @@
+# pup
+
+> Command line HTML parsing tool.
+
+- Transform a raw HTML file into a cleaned, indented, and colored format:
+
+`cat {{index.html}} | pup --color`
+
+- Filter HTML by element tag name:
+
+`cat {{index.html}} | pup '{{tag}}'`
+
+- Filter HTML by id:
+
+`cat {{index.html}} | pup '{{div#id}}'`
+
+- Filter HTML by attribute value:
+
+`cat {{index.html}} | pup '{{input[type="text"]}}'`
+
+- Print all text from the filtered HTML elements and their children:
+
+`cat {{index.html}} | pup '{{div}} text{}'`
+
+- Print HTML as JSON:
+
+`cat {{index.html}} | pup '{{div}} json{}'`