On `dev`: Update "Why use Organizations on GH & HF"

[egrace479]

Why use the Institute GH & HF pages can both be changed to "why use our organization GH/HF" (alternatively, "the organization"), italics used to highlight difference only.

[egrace479]

Or perhaps they should actually be "Why use the GH/HF Organization"?

[egrace479]

Completed in #54.