chore: prettify splashscreen

chore: removed unused var
feat: added custom  mesh as landmark

feat: added waxholm pt from camilla

rxjs: https://github.com/ReactiveX/rxjs/issues/3989
ngx-bootstrap:  `ngx-bootstrap/component-loader` no longer exported
webpack:  `optionsSchema.definitions.output.properties.path.description`
`TypeError: Cannot read property 'properties' of undefined`

fixes #91

now uses worker to parse, and render on a single layer,
should improve performance when rendering lots of landmarks

retrieved data may be array, maybe object

Should have been debounce, and the behavious is weird

loaded in the wrong template space