Readme.md Missing/inconsistent punctuation

[stevehackreactor]

Current Behavior

The list describing Lozad.js following the banner in Readme.md is inconsistent and does not follow English best practices for bullet points.

(potential issue)
There are several instances of missing Oxford commas in the Readme.md.
Although the Oxford comma is generally considered optional, proponents argue it removes ambiguity which I think could only help people understand the documentation (especially those who have English as a second language).

All of these fixes occur in the top portion of the Readme.md before the "Featured in" section.

Bullet points typically adhere to the following format:

• Use a period (full stop) after every bullet point that is a sentence (as these bullets do).
• Use a period after every bullet point that completes the introductory stem.
• Use no punctuation after bullets that are not sentences and do not complete the stem.
• Use all sentences or all fragments, not a mixture.

Possible Solution

Convert each bullet point fragment into a complete sentence using the stem.
For example:
"Lozad.js:

• lazy loads elements performantly using pure JavaScript.
• is a light-weight library (just gzip size 1.25 kb minified and zipped).
• has NO DEPENDENCIES :)
• ..."

Add Oxford commas in three locations:
1: Highly performant, light and configurable lazy loader in pure JS with no dependencies for images, iframes and more, using IntersectionObserver API
2: supports , , iframes, videos, audios, responsive images, background images and multiple background images etc.3: It is written with an aim to lazy load images, iframes, ads, videos or any other element using the recently added Intersection Observer API and MutationObserver with tremendous performance benefits.

I believe cleaning up the initial bullet point list will help this Readme come across even more professionally than it already does. Also, this is my first open-source contribution. I have read the contribution guide but I am still very green so I apologize if I am missing some important step here.