docs(mkdocs): update usage markdown file (#259)

Author: danvergara

docs/usage.md

@@ -93,6 +93,7 @@ Just hit the `BACK` and `NEXT` buttons to go back and forth.
 Key                                     | Description
 ----------------------------------------|---------------------------------------
 <kbd>Ctrl+Space</kbd>                   | If the query panel is active, execute the query
+<kbd>Ctrl+D</kbd>                       | Cleans the whole text from the query editor, when the editor is selected
 <kbd>Enter</kbd>                        | If the tables panel is active, list all the rows as a result set on the rows panel and display the structure of the table on the structure panel
 <kbd>Ctrl+S</kbd>                       | If the rows panel is active, switch to the schema panel. The opposite is true
 <kbd>Ctrl+F</kbd>                       | If the rows panel is active, switch to the constraints view. The opposite is true
@@ -109,6 +110,11 @@ Key                                     | Description
 <kbd>l</kbd>                            | Horizontal scrolling on the panel. Views: rows, constraints, structure and indexes
 <kbd>Arrow Left</kbd>                   | Horizontal scrolling on the panel. Views: rows, constraints, structure and indexes
 <kbd>h</kbd>                            | Horizontal scrolling on the panel. Views: rows, constraints, structure and indexes
+<kbd>h</kbd>                            | Horizontal scrolling on the panel. Views: rows, constraints, structure and indexes
+<kbd>g</kbd>                            | Move cursor to the top of the panel's dataset. Views: rows, constraints, structure and indexes
+<kbd>G</kbd>                            | Move cursor to the bottom of the panel's dataset. Views: rows, constraints, structure and indexes
+<kbd>Ctrl-F</kbd>                       | Move down by one page. Views: rows, constraints, structure and indexes
+<kbd>Ctrl-B</kbd>                       | Move up by one page. Views: rows, constraints, structure and indexes
 <kbd>Ctrl+c</kbd>                       | Quit