Put note about class-side initialization of TBBlog - chapter 4

[Bajger]

There should be a note in chapter 4 about class side initialization of TBBlog class. Since it is invoked explicitly by user, class is initialized (and Mongo memory DB) only when this initialized method is called by user. Therefore note to Save image right after initialization in order to persist state of DB, otherwise DB won't be initialized next time image is opened.
Current state:

The ==reset== class method re-initializes the database. The ==initialize== class method ensures that the database is initialized when we load TinyBlog's code. Do not forget to execute expression ==TBBlog initialize== to ensure that the database is initialized.

Proposal to add right after that:
Note: Please save your image right after you evaluated initialize method. Class side initialization is done only when explicitly evaluated by user. Therefore TBBlog initialization might be lost, if you quit the image without saving changes.

[hogoww]

For additional details, see this discord post which initialized this issue:
https://discord.com/channels/223421264751099906/359632451674570754/1007534503461392404

[Ducasse]

Thanks I will have a look.
If you have a suggestion for the place it will help me.

[Bajger]

I would add note right after this line:

TinyBlog-EN/Chapters/Chap04-TinyBlog-VoyageMongo-EN.pillar

Line 33 in fb3d89c

The ==reset== class method re-initializes the database. The ==initialize== class method ensures that the database is initialized when we load TinyBlog's code. Do not forget to execute expression ==TBBlog initialize== to ensure that the database is initialized.

[Ducasse]

Thanks a lot!!