Development Instructions?

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Hi! I was hoping to play around with the source code, but when I go into gae and type `go run main.go` I find that (for some reason) it cannot find functions that are in main (but I clearly see them):

```
# command-line-arguments
./main.go:14:42: undefined: handleGopherAPI
./main.go:15:37: undefined: handleRecentGophers
./main.go:17:26: undefined: brandingHandler
./main.go:18:22: undefined: handleSave
./main.go:19:37: undefined: handleGopher
./main.go:20:31: undefined: handleGophersCount
./main.go:21:22: undefined: handleGrid
```
There is also a run.sh script with a python script that doesn't seem to be present in the repository. Am I running something from the wrong folder, or is my go setup wrong? For some context:

```
$ go version
go version go1.16.5 linux/amd64
```
and I've cloned this on my go path. Thank you!

Start in gae/main.go and inspect the repository's run.sh, comparing the documented or scripted way to start the application with running main.go directly. Clarify the correct working directory and startup command, and document what should happen with the referenced Python script so a fresh contributor can run the project successfully.

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