Implement io.Reader, io.Writer for quote database

[servusdei2018]

Refactored quoteFile into an io.Reader and io.Writer interface at the quotes.go level. Additionally, the logic in theory.go was simplified to reduce allocations by eliminating the variable sentence. A multi-stage Dockerfile was also introduced, resulting in a final stage image that is ~8% of its original size.

Two notes regarding the Dockerfile:

• if any CGO-requiring dependency is introduced, the image gcr.io/distroless/static-debian12 should be switched to gcr.io/distroless/base-debian12 so that the image includes the appropriate glibc shared objects
• if spatial optimization is of utmost concern, go build may be switched to go build -ldflags="-s -w" in order to strip the DWARF tables and symbol table. This will result in a smaller binary at the cost of being able to debug the binary with gdb or delve

[Alextopher]

Great progress! I think this will support further testing. I will run this in production for the day and merge tomorrow.

[bashawhm]

Looks good to me! I don't know docker, but all the Go changes seem good :)