Tweaked gitignore

gitignore removed all composer and npm files, so automated builds would fail

conf/site/node_modules/collect.js/docs/api/sum.md

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+# `sum()`
+
+The sum method returns the sum of all items in the collection:
+
+```js
+collect([1, 2, 3]).sum();
+
+// 6
+```
+
+If the collection contains nested arrays or objects, you should pass a key to use for determining which values to sum:
+
+```js
+const collection = collect([
+  { name: 'My story', pages: 176 },
+  { name: 'Fantastic Beasts and Where to Find Them', pages: 1096 },
+]);
+
+collection.sum('pages');
+
+// 1272
+```
+
+In addition, you may pass your own callback to determine which values of the collection to sum:
+
+```js
+const collection = collect([
+  { name: 'Desk', colors: ['Black', 'Mahogany'] },
+  { name: 'Chair', colors: ['Black'] },
+  { name: 'Bookcase', colors: ['Red', 'Beige', 'Brown'] },
+]);
+
+const total = collection.sum(product => product.colors.length);
+
+// 6
+```
+
+[View source on GitHub](https://github.com/ecrmnn/collect.js/blob/master/src/methods/sum.js)