Typos in architecture doc

[mhrivnak]

The architecture.md doc includes some typos. In the last paragraph "Catalog (Registry) Design":

"Within a package, channels which point to a particular CSV." This is not a valid sentence. Perhaps the word "which" should be removed? Or maybe the rest of the sentence is missing?

"Because CSVs explicitly reference the CSV that they replace, a package manifest provides the catalog Operator needs to update a CSV to the latest version in a channel (stepping through each intermediate version)." This sentence appears to merge into some other sentence around the words "provides the catalog Operator needs to update". I don't have enough domain knowledge to suggest a fix.

[ecordell]

Thanks for catching this! Made a PR to fix the issues you found.