chore(book): document missing CLI arguments (#3610)

book/cli/import.md

@@ -7,13 +7,6 @@ $ reth import --help
 
 Usage: reth import [OPTIONS] <IMPORT_PATH>
 
-Arguments:
-  <IMPORT_PATH>
-          The path to a block file for import.
-          
-          The online stages (headers and bodies) are replaced by a file import, after which the
-          remaining stages are executed.
-
 Options:
       --config <FILE>
           The path to the configuration file to use.
@@ -44,6 +37,26 @@ Options:
   -h, --help
           Print help (see a summary with '-h')
 
+Database:
+      --db.log-level <LOG_LEVEL>
+          Database logging level. Levels higher than "notice" require a debug build
+
+          Possible values:
+          - fatal:   Enables logging for critical conditions, i.e. assertion failures
+          - error:   Enables logging for error conditions
+          - warn:    Enables logging for warning conditions
+          - notice:  Enables logging for normal but significant condition
+          - verbose: Enables logging for verbose informational
+          - debug:   Enables logging for debug-level messages
+          - trace:   Enables logging for trace debug-level messages
+          - extra:   Enables logging for extra debug-level messages
+
+  <IMPORT_PATH>
+          The path to a block file for import.
+          
+          The online stages (headers and bodies) are replaced by a file import, after which the
+          remaining stages are executed.
+
 Logging:
       --log.persistent
           The flag to enable persistent logs