Add new documentation for array

[manh9203]

Since we are moving from FIXED_LIST to ARRAY and adding more vector operations for it, we should have a separate documentation page for ARRAY data type.

Note: This issue should be addressed after #103 is merged and the new version is released.

[prrao87]

@manh9203 here's the latest docs for the FIXED-LIST and VAR-LIST data types.

Per this issue, do you think the FIXED-LIST should be removed from this section and we should add a new type called ARRAY instead? Or is there a deprecation period where both are active?

[manh9203]

@prrao87 We replaced FIXED-LIST by ARRAY in our nightly build, but it's not available on v0.3.2 yet, so I think we can still keep the docs as it is and add some notes about this.
We are also adding new functions for ARRAY and rename VAR_LIST to LIST, so in the next release, we should have a separate section for ARRAY and its functions.
That's what I know, I think you can discuss with @ray6080 more about it.

[prrao87]

The following PRs are relevant:

• Fixed-list layout rework kuzu#2975
• Add Physical Type ARRAY kuzu#3175
• Rename VAR_LIST to LIST kuzu#3170

Will revisit this once we make the new version release.

[prrao87]

Fixed in #128.