all: add support for the embed package

testdata/embed/a/b/bar.txt

@@ -0,0 +1 @@
+bar

testdata/embed/a/b/foo.txt

@@ -0,0 +1 @@
+foo

testdata/embed/embed.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"embed"
+	"strings"
+)
+
+//go:embed a hello.txt
+var files embed.FS
+
+var (
+	//go:embed "hello.*"
+	helloString string
+
+	//go:embed hello.txt
+	helloBytes []byte
+)
+
+// A test to check that hidden files are not included when matching a directory.
+//go:embed a/b/.hidden
+var hidden string
+
+func main() {
+	println("string:", strings.TrimSpace(helloString))
+	println("bytes:", strings.TrimSpace(string(helloBytes)))
+	println("files:")
+	readFiles(".")
+}
+
+func readFiles(dir string) {
+	entries, err := files.ReadDir(dir)
+	if err != nil {
+		println(err.Error())
+		return
+	}
+	for _, entry := range entries {
+		entryPath := entry.Name()
+		if dir != "." {
+			entryPath = dir + "/" + entryPath
+		}
+		println("-", entryPath)
+		if entry.IsDir() {
+			readFiles(entryPath)
+		}
+	}
+}

testdata/embed/hello.txt

@@ -0,0 +1 @@
+hello world!

testdata/embed/out.txt

@@ -0,0 +1,8 @@
+string: hello world!
+bytes: hello world!
+files:
+- a
+- a/b
+- a/b/bar.txt
+- a/b/foo.txt
+- hello.txt