minor change in docs

Author: ytdHuang

docs/src/users_guide/extensions/cairomakie.md

@@ -1,7 +1,5 @@
 # [Extension for CairoMakie.jl](@id doc:CairoMakie)
 
-## Introduction
-
 This is an extension to support visualization (plotting functions) using [`CairoMakie.jl`](https://github.com/MakieOrg/Makie.jl/tree/master/CairoMakie) library.
 
 This extension will be automatically loaded if user imports both `QuantumToolbox.jl` and [`CairoMakie.jl`](https://github.com/MakieOrg/Makie.jl/tree/master/CairoMakie):
@@ -11,11 +9,13 @@ using QuantumToolbox
 using CairoMakie
 ```
 
-To plot with [`CairoMakie.jl`](https://github.com/MakieOrg/Makie.jl/tree/master/CairoMakie) library, specify the keyword argument `library = Val(:CairoMakie)` for the plotting functions. The supported plotting functions are listed as follows:
+To plot with [`CairoMakie.jl`](https://github.com/MakieOrg/Makie.jl/tree/master/CairoMakie) library, specify the keyword argument `library = Val(:CairoMakie)` for the plotting functions.
 
 !!! warning "Beware of type-stability!"
     If you want to keep type stability, it is recommended to use `Val(:CairoMakie)` instead of `:CairoMakie`. See [this link](https://docs.julialang.org/en/v1/manual/performance-tips/#man-performance-value-type) and the [related Section](@ref doc:Type-Stability) about type stability for more details.
 
+The supported plotting functions are listed as follows:
+
 | **Plotting Function** | **Description** |
 |:----------------------|:----------------|
 | [`plot_wigner`](@ref) | [Wigner quasipropability distribution](https://en.wikipedia.org/wiki/Wigner_quasiprobability_distribution) |