`README.md` lacks straightforward examples

`README.md` is currently showcasing `julia` markdown with commands to run. Showing the outcomes as well would have more impact, see [this example from SoleLogics' README.md](https://github.com/aclai-lab/SoleLogics.jl/tree/02b8637dbb498bcd81c69856a9329b47a190277b#parsing-and-manipulating-formulas):

```julia-repl
julia> φ1 = parseformula("¬p∧q∨(s∨z)")
SyntaxBranch: (¬p ∧ q) ∨ s ∨ z

julia> syntaxstring(φ1; parenthesize_commutatives = true)
"(¬p ∧ q) ∨ (s ∨ z)"

julia> filter(ψ -> height(ψ) == 1, subformulas(φ1))
2-element Vector{SyntaxTree}:
SyntaxBranch: ¬p
SyntaxBranch: s ∨ z

julia> filter(ψ -> natoms(ψ) == 1, subformulas(φ1))
5-element Vector{SyntaxTree}:
Atom{String}: p
Atom{String}: q
Atom{String}: s
Atom{String}: z
SyntaxBranch: ¬p

julia> φ2 = ⊥ ∨ Atom("t") → φ1
SyntaxBranch: ⊥ ∨ t → (¬p ∧ q) ∨ s ∨ z
```

I suggest replacing those `julia` blocks with `julia-repl` blocks showing the full REPL I/O

Open README.md and find the Julia code blocks that currently show commands without results. Use the linked SoleLogics README example as a reference, replacing those blocks with julia-repl blocks that show the full REPL input and output; done means the examples visibly include their outcomes.

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