fix README format issue

Author: ygao61

README.md

@@ -189,8 +189,7 @@ For more advanced options and usage details, see the sections below.
 |------|-------|------|-------------|
 | `--input`  | `-i` | `str` (Required) | Path to the input directory containing the quantification output files or to the HDF5 file itself. |
 | `--output` | `-o` | `str`(Required)  | Path to the output directory.|
-| `--chemistry` | `-c` | `str`(Recommended) | Specifies the chemistry used in the experiment, which determines the range for the empty_drops step. **Supported options**: '10X_3p_v2', '10X_3p_v3', '10X_3p_v4', '10X_5p_v3', '10X_3p_LT', '10X_HT'. If you used a standard 10X chemistry (e.g., '10X_3p_v2', '10X_3p_v3') and performed quantification with `simpleaf`(v0.19.5 or later), QCatch can usually **infer** the correct chemistry automatically from the metadata. If inference fails, QCatch will stop and prompt you to provide the chemistry explicitly via this flag..
-|
+| `--chemistry` | `-c` | `str`(Recommended) | Specifies the chemistry used in the experiment, which determines the range for the empty_drops step. **Supported options**: '10X_3p_v2', '10X_3p_v3', '10X_3p_v4', '10X_5p_v3', '10X_3p_LT', '10X_HT'. If you used a standard 10X chemistry (e.g., '10X_3p_v2', '10X_3p_v3') and performed quantification with `simpleaf`(v0.19.5 or later), QCatch can usually **infer** the correct chemistry automatically from the metadata. If inference fails, QCatch will stop and prompt you to provide the chemistry explicitly via this flag.|
 | `--save_filtered_h5ad` | `-s` | `flag` (Optional) |If enabled, `qcatch` will save a separate `.h5ad` file containing only the retained cells.|
 | `--gene_id2name_file` | `-g` | `str` (Optional) |File provides a mapping from gene IDs to gene names. The file must be a TSV containing two columns—‘gene_id’ (e.g., ENSG00000284733) and ‘gene_name’ (e.g., OR4F29)—without a header row. If not provided, the program will attempt to retrieve the mapping from a remote registry. If that lookup fails, mitochondria plots will not be displayed.|
 | `--valid_cell_list` | `-l` | `str` (Optional) |File provides a user-specified list of valid cell barcode. The file must be a TSV containing one column with cell barcodes without a header row. If provided, qcatch will skip the internal cell calling steps and and use the supplied list instead|