BUG in Learn Markdown extension: "Evenly Distribute Selected Table" replaces table header row (column headings) with dashes

[sohang3112]

For example, for this table in markdown:

Sample	Temperature (Celcius)	Vibration (mm/s)	Class
1	40	1.0	Pass
2	42	1.2	Pass
3	45	1.1	Pass
4	60	4.5	Fail
5	62	4.8	Fail
6	65	5.0	Fail

Original table code is:

Sample|Temperature (Celcius)|Vibration (mm/s)|Class
---|---|---|---
1  | 40 | 1.0 | Pass
2  | 42 | 1.2 | Pass
3  | 45 | 1.1 | Pass
4  | 60 | 4.5 | Fail
5  | 62 | 4.8 | Fail
6  | 65 | 5.0 | Fail

After selecting table, and choosing "Evenly Distribute Selected Table" in right-click menu, it becomes this (notice header row became replaced by all dashes):

|--------|-----------------------|------------------|-------|
| ---    | ---                   | ---              | ---   |
| 1      | 40                    | 1.0              | Pass  |
| 2      | 42                    | 1.2              | Pass  |
| 3      | 45                    | 1.1              | Pass  |
| 4      | 60                    | 4.5              | Fail  |
| 5      | 62                    | 4.8              | Fail  |
| 6      | 65                    | 5.0              | Fail  |