v1.0: remove two-step dump import

[maryamsulemani97]

Currently, users with v0.20 and below need to follow a two-step process for updating Meilisearch due to different dump versions. With v1.0, all dumps created before and up to Meilisearch v1.0 can be imported into Meilisearch v1.X.Y.

To do

• Update updating.md to remove content on the two-step process
• Update learn/advanced/dumps.md

References

• Spec: Simplify dump version section since v1.0 can import all dumps specifications#203
• Issue on core: Add the support of the dump v1 (Meilisearch v0.20.0 and before) meilisearch#2985
• SME: @dureuill

[dureuill]

Here is a comment where I detail some "quirks" relative to importing a very old (v1) dump, to consider wrt documentation.