Added Control-plane resources requirements.

[Jonsy13]

Signed-off-by: Jonsy13 vedant.shrotria@chaosnative.com

What this PR does / why we need it:
This PR will add resources requirements for control-plane components for Portal ( Platforms used - GKE & KIND )

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

Special notes for your reviewer:

Checklist:

• Fixes #
• Signed the commit for DCO to be passed
• Labelled this PR & related issue with documentation tag

Data gathered from VPA -

// Frontend
    Container Name:  litmusportal-frontend
        Lower Bound:
            Cpu:     25m
            Memory:  262144k
        Target:
            Cpu:     25m
            Memory:  262144k
        Uncapped Target:
            Cpu:     25m
            Memory:  262144k
        Upper Bound:
            Cpu:     478m
            Memory:  499755528

// Backend
    Container Name:  graphql-server
        Lower Bound:
            Cpu:     12m
            Memory:  131072k
        Target:
            Cpu:     12m
            Memory:  131072k
        Uncapped Target:
            Cpu:     12m
            Memory:  131072k
        Upper Bound:
            Cpu:           449m
            Memory:        3828582077
    Container Name:  auth-server
        Lower Bound:
            Cpu:     12m
            Memory:  131072k
        Target:
            Cpu:     12m
            Memory:  131072k
        Uncapped Target:
            Cpu:     12m
            Memory:  131072k
        Upper Bound:
            Cpu:     451m
            Memory:  471500k

// MongoDB
    Container Name:  mongo
        Lower Bound:
            Cpu:     25m
            Memory:  262144k
        Target:
            Cpu:     25m
            Memory:  262144k
        Uncapped Target:
            Cpu:     25m
            Memory:  262144k
        Upper Bound:
            Cpu:     379m
            Memory:  6310616433

[ksatchit]

We can restructure this a bit to provide more detail on the resource req estimation process.

[ksatchit]

we can use some buffer units as well

[Jonsy13]

Merging this PR for this release. cc: @ksatchit