fix(mappings): add missing terminal mapping with note on terminal compatibility

Author: mehalter

src/content/docs/mappings.mdx

@@ -226,16 +226,16 @@ AstroNvim generally relies on `<Leader>` driven mappings, which is default set t
 
 ## Terminal Mappings
 
-| Action                   | Mappings      |
-| ------------------------ | ------------- |
-| Open Floating Terminal   | `Leader + tf` |
-| Open Horizontal Terminal | `Leader + th` |
-| Open Vertical Terminal   | `Leader + tv` |
-| Open Toggle Lazygit      | `Leader + tl` |
-| Open Toggle node         | `Leader + tn` |
-| Open Toggle Python       | `Leader + tp` |
-| Open Toggle btm          | `Leader + tt` |
-| Toggle Current Terminal  | `<F7>`        |
+| Action                   | Mappings                                        |
+| ------------------------ | ----------------------------------------------- |
+| Open Floating Terminal   | `Leader + tf`                                   |
+| Open Horizontal Terminal | `Leader + th`                                   |
+| Open Vertical Terminal   | `Leader + tv`                                   |
+| Open Toggle Lazygit      | `Leader + tl`                                   |
+| Open Toggle node         | `Leader + tn`                                   |
+| Open Toggle Python       | `Leader + tp`                                   |
+| Open Toggle btm          | `Leader + tt`                                   |
+| Toggle Current Terminal  | `<F7>` or `<C-'>` (not all terminals supported) |
 
 ## UI/UX Mappings