Line numbers are wrong for the schema with multiline description

[schafle]

Schema parsed by gqlparser does not consider newlines in the multiline descriptions and thus line numbers are off if there are multi-line descriptions present in the schema.

Code to reproduce the issue

package main

import (
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/vektah/gqlparser/v2/ast"
	"github.com/vektah/gqlparser/v2/parser"
)

func TestSchemaParser(t *testing.T) {
	t.Run("schema without description", func(t *testing.T) {
		schema, parseErr := parser.ParseSchema(&ast.Source{
			Input: `type User {
  				name: String!
			}
			type query {
  				me: User!
			}
			`,
		})
		assert.Nil(t, parseErr)
		assert.Equal(t, schema.Definitions.ForName("query").Position.Line, 4)
	})
	t.Run("schema with single line description", func(t *testing.T) {
		schema, parseErr := parser.ParseSchema(&ast.Source{
			Input: `type User {
  				name: String!
			}
			"""some description"""
			type query {
  				me: User!
			}
			`,
		})
		assert.Nil(t, parseErr)
		assert.Equal(t, schema.Definitions.ForName("query").Position.Line, 5)
	})
	t.Run("schema with multi-line description", func(t *testing.T) {
		schema, parseErr := parser.ParseSchema(&ast.Source{
			Input: `type User {
  				name: String!
			}
			"""
				some 
				description
			"""
			type query {
  				me: User!
			}
			`,
		})
		assert.Nil(t, parseErr)
		assert.Equal(t, schema.Definitions.ForName("query").Position.Line, 8)
	})
}

Test schema with multi-line description should not fail.

[StevenACoffman]

Oh gosh, thank you! I would really appreciate a PR to contribute those test cases as well as a fix.

[schafle]

@StevenACoffman PR #230 fixes the issue. Can you take a look?

[StevenACoffman]

Thanks! Sorry I was out of town.