fix typo in man page

Signed-off-by: Stephan Lachnit <stephanlachnit@protonmail.com>

data/mangohud.1

@@ -11,11 +11,11 @@ mangohud \- enable MangoHud on any application
 MangoHud is a Vulkan/OpenGL overlay for monitoring FPS, temperatures, CPU/GPU load and more.
 
 .SH USAGE
-MangoHud can be enabled for Vulkan applications by setting \fBMANGOHUD=1\fR as envrionment variable.
+MangoHud can be enabled for Vulkan applications by setting \fBMANGOHUD=1\fR as environment variable.
 .br
 To load MangoHud for any application, including OpenGL applications, the \fBmangohud\fR executable can be used. It preloads a library via ld into the application.
 .br
-Note: some OpenGL applications may also need dlsym hooking. This can be done by passing option \fB--dlsym\fR or by setting \fBMANGOHUD_DLSYM=1\fR as envrionment variable.
+Note: some OpenGL applications may also need dlsym hooking. This can be done by passing option \fB--dlsym\fR or by setting \fBMANGOHUD_DLSYM=1\fR as environment variable.
 
 .SH CONFIG
 MangoHud comes with a config file which can be used to set configuration options globally or per application. The priorities of different config files are:
@@ -30,9 +30,9 @@ $XDG_CONFIG_HOME/MangoHud/MangoHud.conf
 .LP
 An example config file is located in /usr/share/doc/mangohud/MangoHud.conf, containing all available options.
 .LP
-A custom config file location can also be specified with the \fBMANGOHUD_CONFIGFILE\fR envrionment variable.
+A custom config file location can also be specified with the \fBMANGOHUD_CONFIGFILE\fR environment variable.
 .br
-Config options can also be set with the \fBMANGOHUD_CONFIG\fR envrionment variable. This takes priority over any config file.
+Config options can also be set with the \fBMANGOHUD_CONFIG\fR environment variable. This takes priority over any config file.
 
 .SH EXAMPLES
 OpenGL: \fBmangohud glxgears\fR