Add note for others processors compatibility

[sturmenta]

pull request to modify the docs -> akash-network/docs#239

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In the documentation it is clearly stated that only x86_64 processors are supported for Akash deployments

But

From a mac with m1 processor I was able to run my deploys to akash network indicating at the moment of building the docker image that the target platform is linux/amd64.

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without specifying that the target platform is linux/amd64 my images did not work

after specifying this my docker images work on akash network

[baktun14]

That's actually a good idea to specify it. I've troubleshooted a lot of deployments with the wrong architecture 😅. Thanks!