readability/improvements to asset filter function

[mattlub]

To improve slightly here

3 things:

• instead of indexOf() !== -1, includes is more semantic - docs
• I would separate out the search term into a variable, so it reads more like asset.name.includes(searchTerm)
• The search term could be simplified, after you note that this.state.search.length !== 0 could be replaced by this.state.search, since it's a string (and "" is falsey).