look: add page

pages/osx/look.md

@@ -0,0 +1,11 @@
+# look
+
+> Look for lines in sorted file.
+
+- Look for lines which begins with the given prefix:
+
+`look {{prefix}} {{file}}`
+
+- Look for lines ignoring case:
+
+`look -f {{prefix}} {{file}}`