[ENH] Added white space after table

The next line following the table would otherwise be displayed as an extra row in the table. This was the case directly following the "Specific EEG fields MUST be present" table containing the `EEGReference`.

src/04-modality-specific-files/03-electroencephalography.md

@@ -123,6 +123,7 @@ Specific EEG fields MUST be present:
 | SamplingFrequency  | REQUIRED              | [number][]                           | Sampling frequency (in Hz) of all the data in the recording, regardless of their type (for example, 2400).                                                                                                                                                                                                                                                      |
 | PowerLineFrequency | REQUIRED              | [number][] or `"n/a"`                | Frequency (in Hz) of the power grid at the geographical location of the EEG instrument (for example, 50 or 60).                                                                                                                                                                                                                                                 |
 | SoftwareFilters    | REQUIRED              | [object][] of [objects][] or `"n/a"` | [Object][] of temporal software filters applied, or `"n/a"` if the data is not available. Each key:value pair in the JSON object is a name of the filter and an object in which its parameters are defined as key:value pairs. For example, `{"Anti-aliasing filter": {"half-amplitude cutoff (Hz)": 500, "Roll-off": "6dB/Octave"}}`.                          |
+
 SHOULD be present:
 
 | **Key name**               | **Requirement level** | **Data type**                        | **Description**                                                                                                                                                                                                                                                                                                                        |