Very minor: files-as-dag.md

[kvutien]

In files-as-dag.md, step 2, the blob sizes in the tutorial screen shot don't match the actual displayed sizes, although the CIDs do match. Maybe the API has changed?

QmPHPs1P3JaWi53q5qqiNauPhiTqa3S1mbszcVPHKGNWRh 262144 
QmPCuqUTNb21VDqtp5b8VsNzKEMtUsZCCVsEUBrjhERRSR 262144 
QmS7zrNSHEt5GpcaKrwdbnv1nckBreUxWnLaV4qivjaNr3 262144 
QmQQhY1syuqo9Sq6wLFAupHBEeqfB8jNnzYUSgZGARJrYa 76137

Another minor suggestion. The Primer is awesome. But does it assume that the reader will go sequentially through the lessons?

The question is because I stumbled upon the lesson 1 of the Tutorial on Merkel tree. It was not said that the ipfs daemon should be running. I did some exploration and found it in Lesson 2 of the first tutorial.

Maybe we can repeat by copy-paste at the beginning of each tutorial that the ipfs daemon should be running? It's just a suggestion from a beginner.