docs: Change form composition graph

[SzymonNadbrzezny]

... for improving readability in dark mode

Solves: #1258

[Balastrong]

Thanks!

[SzymonNadbrzezny]

Mermaid graph code as well if anyone might need it in the future.

graph TD;

    S1 --"Yes"--> S2
    S1 --"No"--> S3

    S3 --"Yes"--> S4
    S3 --"No"-->S5

    S5 --"Yes"--> S6
    S5 --"No"--> S7

    S6 --"Yes"--> S8
    S6 --"No"--> S9

    S7 --"Yes"--> S10
    S7 --"No"--> S11
    
    S1["Do you need to reuse state (like defaultValues)?"];
    S2["Use 'formOptions()"];
    S3["Do you need to custom validation functions?"];
    S4["Wrap 'useForm' hook into custom app hook"];
    S5["Do you need to reuse custom UI components?"];
    S6["Do you need access to the 'field'?"];
    S7["Do you need to reuse whole subsections of your form?"];
    S8["Use 'createFormHooks''s 'fieldComponents' (EG: 'TextInput' and 'NumberInput')"];
    S9["Use 'createFormsHook''s 'formComponents' (EG: 'SubmitButton')"];
    S10["Use 'withForm' from 'createFromHook'"];
    S11["Use 'form.Subscribe' and 'form.Field'"];