Added demo product CSV from Tet's tutorial to readme
Added demo product CSV from Tet's tutorial to readme

mwcm/Kauai,CodeKiwi/dirt,montalvomiguelo/Timber,iamdeaneyelid/timber-grunt,iamdeaneyelid/timber-grunt,cimocimocimo/Theia-Shopify-Theme,alexclarkofficial/newbury-theme,eugenelardy/shopifytheme,swapkats/Materify,kipjib/Timber,gridmechanic/Timber,mwcmitchell/Kauai,Klaudit/Timber,CodeKiwi/dirt,iamdeaneyelid/timber-grunt,tikn/Timber,alexclarkofficial/newbury-theme,mwcmitchell/Kauai,CodeKiwi/dirt,wad3inthewater/timber-theme,vovaane/timber,Shine18/Timber,CodeKiwi/dirt,zacwasielewski/Timber,wad3inthewater/timber-theme,Shopify/Timber,swapkats/Materify,graygilmore/timber-grunt,eugenelardy/shopifytheme,cimocimocimo/Theia-Shopify-Theme,graygilmore/timber-grunt,triskybro/Timber,CodeKiwi/dirt,Klaudit/Timber,vovaane/timber,tikn/Timber,mwcmitchell/Kauai,mwcm/Kauai,aboutjax/benny,kipjib/Timber,humancopy/Timber,aboutjax/benny,triskybro/Timber,VirtoCommerce/Timber,montalvomiguelo/Timber,Shine18/Timber,ajmalafif/prime,mwcm/Kauai,aboutjax/benny,zacwasielewski/Timber,gridmechanic/Timber,Shopify/Timber,humancopy/Timber