Hi, I'm having trouble with breaking long lines in """ delimited strings using a backslash. This is called a "line ending backslash" in the toml spec.

Reproducer:

package main

import (
	"fmt"
	"os"

	"github.com/BurntSushi/toml"
)

const in = `f = """
a\
b
c
"""`

func main() {
	var out map[string]string
	if _, err := toml.Decode(in, &out); err != nil {
		fmt.Fprintf(os.Stderr, "error: %v\n", err)
		os.Exit(1)
	}

	fmt.Println(out["f"])
}

Expected output, which is generated with BurntSushi/toml v0.3.1:

ab
c

Output with BurntSushi/toml v1.2.1:

abc

Any chance of fixing this? Thanks!