Fix several documentation typos across training references

[JackTheGit]

Fix several documentation typos:

• conig.yml → config.yml
• internaly → internally
• depencies → dependencies
• differen → different
• remove duplicated words (the the, And and, how to to)

Documentation only, no functional changes.

[JackTheGit]

Added a small follow-up commit:

• fixed checkpoint_id typos
• replaced a TODO with a small StorageMeta example

Documentation only, no functional changes.