Fix typos reported by Godo

Author: rubenwardy

README.md

@@ -186,4 +186,4 @@ Replace spaces with underscores ( _ )
 
 Please note that the above is a guideline on how to make good chapter, but isn't
 exhustive and there are many exceptions. The priority is explaining the concepts
-to the reader efficiently and in a way which is understandably.
+to the reader efficiently and in a way which is understandable.

chapters/folders.md

@@ -22,7 +22,7 @@ are placed. These folders need to be placed in a mod location such as
 minetest/mods. Mods can be grouped into mod packs which are explained below.
 
 A "mod name" is used to refer to a mod. Each mod should have a unique mod name,
-which you can choose - a good mod name describes what the mod does.
+which you can choose - a good mod name should describe what the mod does.
 Mod names can be made up of letters, numbers, or underscores. The folder a mod is
 in needs to be called the same as the mod name.
 

chapters/nodes_items_crafting.md

@@ -60,7 +60,7 @@ minetest.register_craftitem("mymod:diamond_fragments", {
 })
 {% endhighlight %}
 
-Item definitions like seen above are usually made up of a unique
+Item definitions like the one seen above are usually made up of a unique
 [item string](#item-strings) and a definition table. The definition table
 contains attributes which affect the behaviour of the item.