Started writing documentation and adding examples

json.go

@@ -5,6 +5,9 @@ import (
 	"io"
 )
 
+// ToJSON is a filter function which converts each line from the source to a JSON structure.
+// The result is a line-terminated list of JSON objects.
+// The passed in function is to return a Go value that can be marshalled to JSON value.
 func ToJSON(fn func(line string) any) func(r io.Reader, w io.Writer) error {
 	return func(r io.Reader, w io.Writer) error {
 		return eachLine(r, func(line string) (err error) {