Remove backticks

Author: kgryte

lib/node_modules/@stdlib/math/base/special/polygamma/docs/repl.txt

@@ -1,13 +1,13 @@
 
 {{alias}}( n, x )
-    Evaluates the polygamma function of order `n`, i.e. the `(n+1)`th derivative
+    Evaluates the polygamma function of order `n`; i.e., the (n+1)th derivative
     of the natural logarithm of the gamma function.
 
-    If `n` is not a non-negative `integer`, the function returns `NaN`.
+    If `n` is not a non-negative integer, the function returns `NaN`.
 
-    If `x` is `0` or a negative `integer`, the function returns `NaN`.
+    If `x` is zero or a negative integer, the function returns `NaN`.
 
-    If provided `NaN` as either parameter, the `function` returns `NaN`.
+    If provided `NaN` as either parameter, the function returns `NaN`.
 
     Parameters
     ----------