Pycomplexheatmap

(1). [add center in legend_kws of plot_cmap_legend](https://github.com/DingWB/PyComplexHeatmap/commit/a4036211715a813ff7976136434e521e642c2a23)
(2). [update anno_img](https://github.com/DingWB/PyComplexHeatmap/commit/ea925cb4525ccbdbab9e4a8e519f2e750e649d18)
(3). [add supports for palettable cmap](https://github.com/DingWB/PyComplexHeatmap/commit/7ed9bae73098b431b5d5cc821e87f578b1056731)

(1). Normalized the S in dotHeatmap globally instead of only in split heatmap.
(2). Align the xlabel and ylabel to the center of ax_heatmap, instead of ax.

Minor update:
(1). update the bug of color when type(cmap) == dict and not hue is None in dotHeatmap
(2). Add [gene_enrichment_analysis.ipynb](https://github.com/DingWB/PyComplexHeatmap/blob/main/notebooks/gene_enrichment_analysis.ipynb) in docs

(1). Fix the bug for the mismatch of dot size in the legend and dot size in the heatmap
(2). Allow custom `arrowprops` in `anno_label`
(3). Use `max_s` in replace of `ratio` in DotClustermapPlotter and dotHeatmap2d
(4). Add param `dot_legend_marker` in DotClustermapPlotter
(5). Update docs

FIx bug for the vmin,vmax and scale in DotClustermapPlotter and dotHeatmap2d

(1). Add anno_lineplot
(2). Parameter `colors` of anno_barplot can be a dict
(3) Set the grid to False in default for all kinds of annotations