doc: Fix a broken link
doc: Fix a broken link

Fixes #258
Mephistophiles/jansson,wirebirdlabs/featherweight-jansson,npmccallum/jansson,markalanj/jansson,bstarynk/jansson,AmesianX/jansson,npmccallum/jansson,AmesianX/jansson,markalanj/jansson,akheron/jansson,markalanj/jansson,wirebirdlabs/featherweight-jansson,Mephistophiles/jansson,bstarynk/jansson,akheron/jansson,bstarynk/jansson,akheron/jansson