doc/go1.17: note deprecation of 'go get' for installing commands
doc/go1.17: note deprecation of 'go get' for installing commands

Fixes #43684

Change-Id: I8982f6816c002c71e62f37a926c8543e34b8b785
Reviewed-on: https://go-review.googlesource.com/c/go/+/329549
Trust: Jay Conrod <f3fadaedc813344da5ec13b41e26596889cc5baa@google.com>
Reviewed-by: Bryan C. Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>

nawawi/go,golang/go,golang/go,nawawi/go,CAFxX/go,cloudflare/go,nawawi/go,golang/go,golang/go,CAFxX/go,nawawi/go,cloudflare/go,golang/go,golang/go,CAFxX/go,CAFxX/go,golang/go,cloudflare/go,cloudflare/go,nawawi/go,CAFxX/go,nawawi/go,cloudflare/go,golang/go,cloudflare/go,cloudflare/go,nawawi/go,CAFxX/go,cloudflare/go,CAFxX/go,nawawi/go,CAFxX/go