update to vega@5

also update handlebars and lodash to fix security issues

add handlebar-helpers

v0.17.0

0.17.0

support loading variables from shell environment files

Syntax:

mdtk --envfiles /etc/profile --envfiles .env

npm audit fix

v0.15.0

0.15.0

v0.14.0

add mdtk bootstrap command

v0.13.0

experimental support for video

enable background control on each slide (revealjs)

enable use of @section(data-background-*, xxx) atrule

• fix background image resolution on section tags
• assign path/line attr based on hr location

v0.12.0

let containers interrupt other block level elements

v0.11.0

don't require newline after opening and before closing container markup
don't disable hr in containers plugin

v0.10.3

hr chars should only be interspersed with spaces

Fixes syntax such as:

- *hello*: - world -

Where the three "-" were treated as an hr "---" despite being interspersed with non-whitespace characters.