[docs/lua-api-mod.md] Documentation improved for 'mod:path()'.

docs/lua-api-gui-image.md

@@ -7,7 +7,7 @@ gui:image {
 	name = "img_background", -- mandatory
 	pos = {x = 0, y = 0},    -- mandatory
 
-	texture = "mods/default/textures/gui/workbench.png",
+	texture = mod:path() .. "/textures/gui/workbench.png",
 	clip = {x = 0, y = 0, width = 176, height = 166},
 }
 ```
@@ -55,6 +55,8 @@ Full path of the texture. Relative to the repo root.
 
 Example:
 ```lua
-texture = "mods/default/textures/gui/workbench.png"
+texture = mod:path() .. "/textures/gui/workbench.png"
 ```
 
+See [this page](/lua-api-mod#path) for more details about `mod:path()`.
+

docs/lua-api-gui-progress-bar.md

@@ -14,7 +14,7 @@ gui:progress_bar {
 	meta = "item_progress",
 	max_value = 200,
 
-	texture = "mods/default/textures/gui/furnace.png",
+	texture = mod:path() .. "/textures/gui/furnace.png",
 	clip = {x = 176, y = 14, width = 24, height = 17},
 }
 ```
@@ -101,9 +101,11 @@ Full path of the texture. Relative to the repo root.
 
 Example:
 ```lua
-texture = "mods/default/textures/gui/furnace.png"
+texture = mod:path() .. "/textures/gui/furnace.png"
 ```
 
+See [this page](/lua-api-mod#path) for more details about `mod:path()`.
+
 ### `type`
 
 Type of the progress bar.

docs/lua-api-gui-scroll-bar.md

@@ -7,7 +7,7 @@ gui:scroll_bar {
 	name = "scroll_bar",
 	pos = {x = 175, y = 18},
 
-	texture = "mods/default/textures/gui/tabs.png",
+	texture = mod:path() .. "/textures/gui/tabs.png",
 	clip = {x = 232, y = 0, width = 12, height = 15},
 
 	widget = "inv_creative_items",
@@ -78,9 +78,11 @@ Full path of the texture. Relative to the repo root.
 
 Example:
 ```lua
-texture = "mods/default/textures/gui/tabs.png"
+texture = mod:path() .. "/textures/gui/tabs.png"
 ```
 
+See [this page](/lua-api-mod#path) for more details about `mod:path()`.
+
 ### `widget`
 
 Name of the inventory widget which will be affected by the scroll bar.

docs/lua-api-mod.md

@@ -62,6 +62,12 @@ Returns the string ID of the mod.
 
 Returns the path of the mod, relative to current working directory.
 
+**Note:** In callbacks like `on_block_activated`, the `mod` object may be invalid.
+You'll need to create a local variable at the beginning of the file:
+```lua
+local modpath = mod:path()
+```
+
 ## Registration functions
 
 ### `block`