Fix Image path

issue: #54
PR: #56

nimibOutDir and nimibSrcDir

added compile-time switches to override nbHomeDir: #53
Mainly required for Nimiboost, also useful for nimibook.
We will clean up path handling later and also document more explicitly this, hopefully before 0.2.

re-release to fix nimble version

I forgot to bump version in nimble file when releasing 0.1.1, new release to fix this

fixes/requirements for scinim/getting-started

see discussion in various issues https://github.com/SciNim/getting-started/issues, in particular this release is to address SciNim/getting-started#12

• add nbPostInit mechanism to customize document (#32)
• fix (breaking): code output is escaped by default
• fix (breaking): code output is not stripped anymore
• fix: nbDoc.write will create directories if not existing (#44)