Document minimum requirement

[nabuskey]

We need to document the minimum machine spec need to use idpbuilder with core packages only.

  Resource           Requests     Limits
  --------           --------     ------
  cpu                1150m (14%)  100m (1%)
  memory             508Mi (1%)   390Mi (1%)
  ephemeral-storage  0 (0%)       0 (0%)
  hugepages-1Gi      0 (0%)       0 (0%)
  hugepages-2Mi      0 (0%)       0 (0%)

According to this, it should be 2 vCPUs and 1 GB memory. But realistically, it should have at least 4 vCPUs and 4 GB ram available to ensure whatever users deploy actually works.