Update redirect to "zf-apigility/welcome"

- per zfcampus/zf-apigility@871f9b0bb
Fix layout

- Use apigility logo
- Remove "API First"/"AP1st"/"API1st" language
Restructuring of layout content

- Adopt navbar-header for logo
- Use header tag for navbar
- Move footer tag outside content container
- Make containers container-fluid to allow them to be responsive
Remove container-fluid

- looked ugly
Better footer markup
Fixed navbar markup

- so that the navbar is an appropriate height, and so navbar items will be
  positioned correctly.