update exports.md

Author: MichaelCurrin

recipes/make/exports.md

@@ -20,25 +20,28 @@ I don't know if these defaults are actually used here.
     include defaults.mk
 
     check-env :
-      @echo "ENVIRONMENT is only 'prod'. And needed for backwards compatibility. Exporting... ";
-      @export ENVIRONTMENT=prod;
-      @if [ -z $(PROGRAM) ]; then \
-        echo "PROGRAM must be set; export PROGRAM=<program>"; exit 10; \
-      fi
+    	@echo "ENVIRONMENT is only 'prod'. And needed for backwards compatibility. Exporting... ";
+    	@export ENVIRONMENT=prod;
+        @if [ -z $(PROGRAM) ]; then \
+            echo "PROGRAM must be set; export PROGRAM=<program>"; exit 10; \
+        fi
     ```
 
 ## StackOverflow sample
 
 [link](https://stackoverflow.com/questions/24263291/define-a-makefile-variable-using-a-env-variable-or-a-default-value)
 
+Use lines here start with a colon to print only and not execute.
+
 - `Makefile`
     ```Makefile
     T ?= foo
+
     all:
-            : '$(T)'
+        : '$(T)'
     ```
 
-```sh
+```console
 $ make
 : 'foo'
 
@@ -65,11 +68,9 @@ $ make TMPDIR=foo
 foo
 ```
 
-
-
 For debugging, check the value of the token.
 
-B. Only run this on a remote if the logs are private, so no one steals your token on a PR preview. GitHub now hides secrets, does Netlify? Should builds be restricted to only PRs by me and not forks to avoid someone making a preview that expposes a token? The easiest is just private logs.
+B. Only run this on a remote if the logs are private, so no one steals your token on a PR preview. GitHub now hides secrets, does Netlify? Should builds be restricted to only PRs by me and not forks to avoid someone making a preview that exposes a token? The easiest is just private logs.
 
 ```Makefile
 export GITHUB_TOKEN := $(if $(GITHUB_TOKEN), $(GITHUB_TOKEN), '')