Fix line embedding

Signed-off-by: jolheiser <john.olheiser@gmail.com>

README.md

@@ -22,6 +22,7 @@ An entire file:
 
 <!-- emdbed: emdbed_example_test.go -->
 ```go
+// Package emdbed is for embedding "things" in your markdown
 package emdbed
 
 import (
@@ -56,15 +57,15 @@ func Example() {
 
 Just the package:
 
-<!-- emdbed: emdbed_example_test.go L1 L1 -->
+<!-- emdbed: emdbed_example_test.go L2 L2 -->
 ```go
 package emdbed
 ```
 <!-- /emdbed -->
 
-First line until the end of imports:
+Package line until the end of imports:
 
-<!-- emdbed: emdbed_example_test.go L1 /\)/ -->
+<!-- emdbed: emdbed_example_test.go L2 /\)/ -->
 ```go
 package emdbed
 

emdbed_example_test.go

@@ -1,3 +1,4 @@
+// Package emdbed is for embedding "things" in your markdown
 package emdbed
 
 import (

io.go

@@ -25,7 +25,15 @@ func (e emdbed) line(line int, end bool) (int, error) {
 	if len(indexes) < line {
 		return 0, fmt.Errorf("file %q has no line %d", e.name, line)
 	}
-	return indexes[line-1][0], nil
+	dec := 1
+	if !end {
+		dec++
+	}
+	var inc int
+	if !end {
+		inc++
+	}
+	return indexes[line-dec][0] + inc, nil
 }
 
 func (e emdbed) regex(pattern string, end bool) (int, error) {