x/website: doc/install has outdated filename for linux

[ipriver]

There is a command on doc/install page that uses an outdated filename that is being shown as an example of how to install go for Linux:
tar -C /usr/local -xzf go1.14.3.linux-amd64.tar.gz

What did you expect to see?

tar -C /usr/local -xzf command should use the latest archive filename for the current go version

What did you see instead?

go1.14.3.linux-amd64.tar.gz filename is statically defined in the markup.

[gopherbot]

Change https://golang.org/cl/253118 mentions this issue: doc/install: fix Linux tab installation command

[jgeiger-trane]

Thanks. I searched for x/website since that's the issue that's created for the "Report an issue" on the website.