Get table of promoter region

[emdann]

Closes #4

Implemented strand-aware selection of region around TSS.

Example usage:

promoters = hsapiens108.promoters(upstream=500, downstream=100)

TO DO

• [ ] Use transcript instead of gene table: we need to call the transcript table, using a join to extract seq_name and seq_strand for each gene (i.e. relies on merging #22 )

[codecov-commenter]

Codecov Report

Merging #34 (36fd565) into main (8e336e9) will increase coverage by 0.55%. The diff coverage is 100.00%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #34 +/- ## ========================================== + Coverage 88.40% 88.96% +0.55% ========================================== Files 6 6 Lines 138 145 +7 ========================================== + Hits 122 129 +7 Misses 16 16 ``` | [Impacted Files](https://codecov.io/gh/scverse/genomic-features/pull/34?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scverse) | Coverage Δ | | |---|---|---| | [src/genomic\_features/ensembl/ensembldb.py](https://codecov.io/gh/scverse/genomic-features/pull/34?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scverse#diff-c3JjL2dlbm9taWNfZmVhdHVyZXMvZW5zZW1ibC9lbnNlbWJsZGIucHk=) | `91.37% <100.00%> (+1.18%)` | :arrow_up: |