feat: allow desc in ---@alias enum

[numToStr]

Now you can add a description to a ---@alias (enum) tag

Syntax

---@alias <name>
---TEXT                  <--- This is now valid
---TEXT                  <--- and there could be more than one
---| ...
---| ...

Emmy

---@alias VMode
---Vim operator-mode motions. Read `:h map-operator`
---| 'line' Vertical motion
---| 'char' Horizontal motion
---| 'v' Visual Block Mode
---| 'V' # Visual Line Mode

Help

VMode                                                                    *VMode*
    Vim operator-mode motions. Read `:h map-operator`

    Variants: ~
        ('line')  Vertical motion
        ('char')  Horizontal motion
        ('v')     Visual Block Mode
        ('V')     Visual Line Mode