docs(en): fix CLI references (no -t / --update flags; -b is a value option)

docs/en-US/configuration/themes.md

@@ -21,12 +21,6 @@ You can also import theme files. You can take inspiration from, or directly use,
 one of the themes bundled with termscp in the `themes/` directory of the
 repository. Import a theme by running:
 
-```sh
-termscp -t <theme_file>
-```
-
-This is also available as:
-
 ```sh
 termscp theme <theme_file>
 ```
@@ -54,7 +48,7 @@ are two quick fixes:
    patched, so download the updated theme from the repository and re-import it:
 
     ```sh
-    termscp -t <theme.toml>
+    termscp theme <theme.toml>
     ```
 
 2. Edit your theme by hand. If you use a custom theme, edit the file and add the