Corrected grammatical error in documentation.

Thanks to @Lemongrass3110

doc/script_commands.txt

@@ -4763,13 +4763,13 @@ If the skill is self or auto-targeting, it will be used immediately; otherwise a
 target cursor is shown.
 
 If <keep requirement> parameter is set to true, the skill's requirements will be checked.
-By default, the requirements for item skills are not checked and therefore the default value is false.
+By default, the requirements for item skills are not checked, and therefore the default value is false.
 
 // When Anodyne is used, it will cast Endure (8), Level 1, as if the actual
 // skill has been used from skill tree.
 605,Anodyne,Anodyne,11,2000,0,100,,,,,10477567,2,,,,,{ itemskill 8,1; },{}
 
-// When Sienna_Execrate_Scroll_1_5 is used, it will cast Sienna Execrate Level 5 and consumes 2 Red_Gemstone.
+// When Sienna_Execrate_Scroll_1_5 is used, it will cast Sienna Execrate Level 5 and consume 2 Red_Gemstones.
 23194,Sienna_Execrate_Scroll_1_5,Level 5 Sienna Execrate,11,10,,10,,,,,0xFFFFFFFF,63,2,,,,,,{ itemskill "WL_SIENNAEXECRATE",5,true; },{},{}
 
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