README fix

Clean up

Adding toolchain and updating documentation

Migrate from Dep to Go Modules

Go Modules are the preferred way to manage dependencies in Go programs
since version 1.11. The migration process involves:

 1. go mod init git.dominic-ricottone.com/~dricottone/image2ascii
    (replace the host as needed)
 2. Replace the host in files requiring an internal module
    (this was specifically image2ascii.go, convert/convert.go,
    convert/resize.go, and convert/resize_test.go)
 3. go mod tidy
 4. rm -rf vendor/ Gopkg.lock Gopkg.toml
 5. go get -u

go.mod now contains all the information required to build the program.

Update install instructions from to `go install`

Looks like `go get` has been deprecated.

New method for installation is `go install <repo-url>@latest`

In this case:

```sh
go install github.com/qeesung/image2ascii@latest
```

Add Awesome badge

Fixed the high cyclomatic complexity issue

Fixed the golint issue

Fixed the golint issue

Disable deploy

Refactor rename the PixelASCII to CharPixel

fixed the go lint issue

Add method to support convert image to pixelASCII matrix

remove useless code

Update README.md

Update README.md

Update README.md

Update README.md

Update README.md

add some examples