chore(Build): Parcel should not try to build declarations
chore(Build): Parcel should not try to build declarations

Avoids error `🚨  /home/nokome/stencila/source/thema/src/declarations.d.ts: Debug Failure. Output generation failed`

stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila