Fix trailing whitespace after opening raw tag breaking formatting

Turns out our "only want the meat" logic was slightly off and made it so
we printed "" when there was whitespace before the newline character.

Ugh.

Fixes #144

src/printer/utils/string.ts

@@ -10,7 +10,7 @@ export const trimEnd = (x: string) => x.trimEnd();
 
 export function bodyLines(str: string): string[] {
   return str
-    .replace(/^\n*|\s*$/g, '') // only want the meat
+    .replace(/^(?: |\t)*\n*|\s*$/g, '') // only want the meat
     .split(/\r?\n/);
 }
 

test/issue-144/fixed.liquid

@@ -0,0 +1,5 @@
+it should format as expected when there's whitespace after the opening comment
+{% comment %}
+  This is a comment
+{% endcomment %}
+<p>hello, world!</p>

test/issue-144/index.liquid

@@ -0,0 +1,5 @@
+debug it should format as expected when there's whitespace after the opening comment
+{% comment %} 
+This is a comment
+{% endcomment %}
+<p>hello, world!</p>

test/issue-144/index.spec.ts

@@ -0,0 +1,6 @@
+import { assertFormattedEqualsFixed } from '../test-helpers';
+import * as path from 'path';
+
+describe(`Unit: ${path.basename(__dirname)}`, () => {
+  assertFormattedEqualsFixed(__dirname);
+});