GP002: Change all .shp to .gpkg

[jeeemil]

GP002

GP002 and also probably GP001 and QGIS kunnille.

Description

Since the data has been updated to be in .gpkg format many exercises still say "add *.shp" as well as many pictures showing the .shp file.

Solution Change the occurrences of .shp in the text to .gpkg and check all the pictures and updated them to have the .gpkg file.

[jeeemil]

Changes to be made in at least:

• [ ] Exercise 1
• [ ] Exercise 3
• [ ] Exercise 4
• [ ] Exercise 7