Update Application constructor docblock
Update Application constructor docblock

Per @Stanimirdim92 in #20, this updates the Application constructor
docblock:

- Fixes the typehint and argument name for the first argument to
  reference a router instead of the dispatcher (which no longer exists).
- Updatese the description to remove the verbiage about piping the route
  middleware, as that's now delayed until first call to `route()`.

mwillbanks/zend-expressive,ezimuel/zend-expressive,grizzm0/zend-expressive,kingjerod/zend-expressive,kynx/zend-expressive,jguittard/zend-expressive,acelaya/zend-expressive,zf2timo/zend-expressive,jguittard/zend-expressive,prolic/zend-expressive,weierophinney/zf-docs-toolchain-experiment,pborreli/zend-expressive,matwright/zend-expressive,matwright/zend-expressive,kingjerod/zend-expressive,kynx/zend-expressive,matwright/zend-expressive,pborreli/zend-expressive,codeliner/zend-expressive,mwillbanks/zend-expressive,kynx/zend-expressive,moderndeveloperllc/zend-expressive,jguittard/zend-expressive,micheh/zend-expressive,prolic/zend-expressive,prolic/zend-expressive,pborreli/zend-expressive,grizzm0/zend-expressive,grizzm0/zend-expressive,nightlinus/zend-expressive