chore: update GIMP keyboard shortcuts configuration

Update various keyboard shortcuts in GIMP configuration file to improve usability and avoid conflicts

.config/GIMP/3.0/shortcutsrc

@@ -207,7 +207,7 @@
 # (action "context-foreground-green-maximum")
 # (action "context-foreground-green-increase-skip")
 # (action "context-brush-spacing-set")
-# (action "edit-fill-fg" "<Primary>comma")
+(action "edit-fill-fg" "<Primary>BackSpace")
 # (action "drawable-rotate-180")
 # (action "plug-in-gflare")
 # (action "gimp-palette-export-text")
@@ -391,7 +391,7 @@
 (action "tools-fuzzy-select" "w")
 # (action "filters-edge-neon")
 # (action "gimp-help-using-selections")
-# (action "file-export" "<Primary>e")
+(action "file-export" "<Primary><Shift><Alt>w")
 # (action "filters-noise-rgb")
 # (action "filters-image-gradient")
 # (action "tools-airbrush-rate-minimum")
@@ -441,7 +441,7 @@
 # (action "context-brush-angle-maximum")
 # (action "context-colormap-foreground-set")
 # (action "image-convert-grayscale")
-(action "image-duplicate")
+(action "image-duplicate" "<Primary>j")
 # (action "dialogs-undo-history")
 # (action "select-feather")
 # (action "select-stroke-last-values")
@@ -547,7 +547,7 @@
 # (action "tools-ink-blob-angle-set")
 # (action "context-tool-select-first")
 # (action "filters-erode")
-# (action "edit-fill-bg" "<Primary>period")
+(action "edit-fill-bg" "<Alt>BackSpace")
 # (action "image-print-size")
 # (action "context-foreground-green-minimum")
 # (action "filters-gegl-color-warp")
@@ -555,7 +555,7 @@
 # (action "tools-handle-transform" "<Shift>l")
 # (action "filters-gaussian-blur")
 # (action "context-colormap-background-previous")
-# (action "image-merge-layers" "<Primary>m")
+(action "image-merge-layers" "<Primary>e")
 # (action "filters-high-pass")
 (action "tools-move" "v")
 # (action "context-pattern-select-previous")