Add doc for find(1)

osx/find.md

@@ -0,0 +1,15 @@
+# find
+
+> Find files under the current directory tree, recursively
+
+- find files by extension
+
+`find {{root_path}} -name {{'*.py'}}`
+
+- run a command for each file
+
+`find {{root_path}} -name {{'*.py'}} -exec {{wc -l {}}} \;`
+
+- find files modified since a certain time
+
+`find {{root_path}} -name {{'*.py'}} -mtime {{-1d}}`