Fix some invalid cross-ref links

Author: dacap

files.md

@@ -14,7 +14,7 @@ Aseprite has its own file format to [save](save.md) your work: `.aseprite` files
 (or `.ase`, [both are the same](/faq/#is-there-any-difference-between-ase-and-aseprite-files)).
 When you save your sprites in an `.aseprite` file you
 will be able to keep all the information intact ([color
-mode](color-mode.md), [layers](layers.md), [frames](frames.md),
+mode](color-mode.md), [layers](layers.md), [frames](animation.md),
 palette, [tags](tags.md), [slices](slices.md), etc.)
 
 Generally you will want to [export your work](exporting.md) to other

save.md

@@ -4,7 +4,7 @@ You can save your sprite using the *File > Save* menu or pressing <kbd>Ctrl+S</k
 
 We highly recommend you to save your sprites in the
 [.aseprite](files.md#aseprite) format, so you keep the full sprite
-information intact ([layers](layers.md), [frames](frames.md),
+information intact ([layers](layers.md), [frames](animation.md),
 etc.). But you can save your sprite as other file types if you don't
 need all this information. For example, you can [open](open.md) a
 `.png` file, editing it, and save it again as `.png` (without using

workspace.md

@@ -36,7 +36,6 @@ with the <kbd>Left Mouse Button</kbd>:
 [Context Bar](context-bar.md) |
 [Sprite Editor](sprite-editor.md) |
 [Status Bar](status-bar.md) |
-[Tabs](tabs.md) |
 [Timeline](timeline.md) |
 [Tool Bar](tool-bar.md) |
 [Menu Bar](menu-bar.md) |