fixes some grammar and clarifies the explanation for the turbine (#66759)

I've noticed some complaints regarding the explanation of the new turbine and its parts, and while I don't think it's that unclear, it could be better. I figured I'd improve the text slightly to be clearer, and fix some small grammar issues while I was around the relevant files.

code/modules/power/turbine/turbine.dm

@@ -564,9 +564,9 @@
 	name = "paper- 'Quick guide on the new and improved turbine!'"
 	info = "<B>How to operate the turbine</B><BR>\
 	-The new turbine is not much different from the old one, just put gases in the chamber, light them up and activate the machine from the nearby computer.\
-	-As you will see there is a new parameter in the computer UI, damage. Yes this machine can be damaged when the heat gets too high, so ensure proper burning temperature in the chamber.\
-	-You can avoid a critial failure by upgrading the parts of the machine, but not stock parts, we implemented 3 new and improved items.<BR>\
-	-These items are: the compressor part, the rotor part and the stator part. All of them can be printed in any engi lathes (both proto and auto).\
-	-There are 4 tiers for these items, only the first one can be printed, the rest must be crafted by hand using the materials shown when examining the part.\
-	-Each tier increases the efficiency (more power) the max reachable RPM and the max temperature that the machine can held (up to fusion temperatures at the last tier!).\
-	-A note of warning, the machine is very inefficient regarding gas consumption and many unburnt gases will pass through. If you want to be cheap you can either pre-burn the gases or add a filtering system to collect them and reuse them."
+	-There is a new parameter that's visible within the turbine computer's UI, damage. The turbine will be damaged when the heat gets too high, according to the tiers of the parts used. Make sure it doesn't get too hot!<BR>\
+	-You can avoid the turbine critically failing by upgrading the parts of the machine, but not with stock parts as you might be used to. There are 3 all-new parts, one for each section of the turbine.<BR>\
+	-These items are: the compressor part, the rotor part and the stator part. All of them can be printed in any engi lathes (both proto and auto).<BR>\
+	-There are 4 tiers for these items, only the first tier can be printed. The next tier of each part can be made by using various materials on the part (clicking with the material in hand, on the part). The material required to reach the next tier is stated in the part's examine text, try shift clicking it!<BR>\
+	-Each tier increases the efficiency (more power), the max reachable RPM, and the max temperature that the machine can process without taking damage (up to fusion temperatures at the last tier!).<BR>\
+	-A word of warning, the machine is very inefficient in its gas consumption and many unburnt gases will pass through. If you want to be cheap you can either pre-burn the gases or add a filtering system to collect the unburnt gases and reuse them."

code/modules/power/turbine/turbine_parts.dm

@@ -95,21 +95,21 @@
 
 /obj/item/turbine_parts/compressor
 	name = "compressor part"
-	desc = "Install in a turbine engine compressor to increase it's performances"
+	desc = "Install in a turbine engine compressor to increase its performance"
 	icon_state = "compressor_part"
 	part_efficiency = 0.25
 	part_efficiency_increase_amount = 0.2
 
 /obj/item/turbine_parts/rotor
 	name = "rotor part"
-	desc = "Install in a turbine engine rotor to increase it's performances"
+	desc = "Install in a turbine engine rotor to increase its performance"
 	icon_state = "rotor_part"
 	part_efficiency = 0.25
 	part_efficiency_increase_amount = 0.2
 
 /obj/item/turbine_parts/stator
 	name = "stator part"
-	desc = "Install in a turbine engine turbine to increase it's performances"
+	desc = "Install in a turbine engine turbine to increase its performance"
 	icon_state = "stator_part"
 	part_efficiency = 0.85
 	part_efficiency_increase_amount = 0.015