Fixed some typos on manual (thanks to Josef Friedrich).

manual/luatex-fonts.tex

@@ -788,7 +788,7 @@ Within reasonable bounds you can extend a font after it has been defined. Becaus
 some properties are best left unchanged this is limited to adding characters.
 
 \startfunctioncall
-font.addcharacters(<number n>, <table> f)
+font.addcharacters(<number> n, <table> f)
 \stopfunctioncall
 
 The table passed can have the fields \type {characters} which is a (sub)table

manual/luatex-nodes.tex

@@ -1248,7 +1248,7 @@ This converts a single type name to its internal numeric representation.
 \libindex {type}
 \libindex {subtype}
 
-In the argument is a number, then the next function converts an internal numeric
+If the argument is a number, then the next function converts an internal numeric
 representation to an external string representation. Otherwise, it will return
 the string \type {node} if the object represents a node, and \type {nil}
 otherwise.