Confusing sentence regarding WebDriver vendor support

[timbru31]

In chapter one in the section Why choose WebDriver (https://github.com/selenium-webdriver-book/manuscript/blob/master/manuscript/ch01_first_steps.adoc#why-choose-webdriver) you tell the reader in bullet point two:

WebDriver is supported by major browser vendors: both Firefox and Chrome are active participants in WebDriver’s development.

I find this sentence confusing. (the vendor is involved in the development, but not the product)
IMO this could be split into more sentences, explaining the situation like this:

• Which browsers have native drivers shipped with them or vendor supported ones? (taking in account that Apple and Microsoft have own implementations, too)
• Which vendors are involved in the development?

Additionally a link to the W3C spec could be added 👍

What do you think? Happy to make a PR if you do agree.