Getting Started page should be more accessible to folks with non-programming background

[2shea]

• Users shouldn't need to reference installation docs on talonvoice.com. Redirecting folks there and back adds friction and can be avoided by filling out installation steps directly on the wiki.
• Add instructions for users who don't use the command line.
• Specifics about Linux are currently very prominent on the page but are not relevant for many users. This information is important, but should be reorganized so it's not so prominent.
• Every choice on the page adds friction (e.g., beta vs. free version or table of speech engines). We should update the flow to assume a default option to keep the flow simple; link to additional options.