doc: implement minor text fixes to path.md

posix -> POSIX
platform specific -> platform-specific

PR-URL: #24118
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>

doc/api/path.md

@@ -288,7 +288,7 @@ added: v0.1.16
 * Returns: {string}
 
 The `path.join()` method joins all given `path` segments together using the
-platform specific separator as a delimiter, then normalizes the resulting path.
+platform-specific separator as a delimiter, then normalizes the resulting path.
 
 Zero-length `path` segments are ignored. If the joined path string is a
 zero-length string then `'.'` will be returned, representing the current
@@ -317,7 +317,7 @@ The `path.normalize()` method normalizes the given `path`, resolving `'..'` and
 
 When multiple, sequential path segment separation characters are found (e.g.
 `/` on POSIX and either `\` or `/` on Windows), they are replaced by a single
-instance of the platform specific path segment separator (`/` on POSIX and
+instance of the platform-specific path segment separator (`/` on POSIX and
 `\` on Windows). Trailing separators are preserved.
 
 If the `path` is a zero-length string, `'.'` is returned, representing the
@@ -543,7 +543,7 @@ On Windows systems only, returns an equivalent [namespace-prefixed path][] for
 the given `path`. If `path` is not a string, `path` will be returned without
 modifications.
 
-This method is meaningful only on Windows system. On posix systems, the
+This method is meaningful only on Windows system. On POSIX systems, the
 method is non-operational and always returns `path` without modifications.
 
 ## path.win32