Fix corresponding upstream source reported in previous commits accordingly

doc/nghttpx.h2r

@@ -19,7 +19,7 @@ FILES
   ignored.
 
   To specify private key and certificate file which are given as
-  positional arguments in commnad-line, use ``private-key-file`` and
+  positional arguments in command-line, use ``private-key-file`` and
   ``certificate-file``.
 
   :option:`--conf` option cannot be used in the configuration file and

examples/libevent-client.c

@@ -50,11 +50,11 @@
 #define ARRLEN(x) (sizeof(x) / sizeof(x[0]))
 
 typedef struct {
-  /* The NULL-terminated URI string to retreive. */
+  /* The NULL-terminated URI string to retrieve. */
   const char *uri;
   /* Parsed result of the |uri| */
   struct http_parser_url *u;
-  /* The authroity portion of the |uri|, not NULL-terminated */
+  /* The authority portion of the |uri|, not NULL-terminated */
   char *authority;
   /* The path portion of the |uri|, including query, not
      NULL-terminated */

src/h2load.cc

@@ -1014,7 +1014,7 @@ Options:
               Number of native threads.
               Default: )" << config.nthreads << R"(
   -i, --input-file=<FILE>
-              Path of a file with multiple URIs are seperated by EOLs.
+              Path of a file with multiple URIs are separated by EOLs.
               This option will disable URIs getting from command-line.
               If '-' is given as <FILE>, URIs will be read from stdin.
               URIs are used  in this order for each  client.  All URIs