Multiple examples as one

In some concepts, there is a single example with a bullet list. IMO it's a bug, there should be more examples instead.

102-03-10:

```
examples:
- |-
* for a given vector stem:[U = U_1 a_1 + U_2 a_2 + ... + U_n a_n], where stem:[U_1 , U_2 , ... , U_n] are the coordinates of *stem:[U]* and stem:[a_1 , a_2 , ... , a_n] are the base vectors, any of the vectors stem:[U_1 a_1 , U_2 a_2 , ... , U_n a_n],

* the projections of a vector normal and tangential to a surface (normal component and tangential component).
```

102-04-49:

```
examples:
- "* symmetric by translation for a periodic configuration, \n\n* symmetric by rotation
of 2π/stem:[n], where stem:[n] is an integer, or by any rotation, \n\n* symmetric
by mirroring, \n\n* and combinations thereof."
```

----

@ronaldtse Confirmation needed if it's really a bug.