Created SC2316 (markdown)

SC2316.md

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+## This applies local to the variable named readonly, which is probably not what you want. Use a separate command or the appropriate `declare` options instead.
+
+
+### Problematic code:
+
+```sh
+local readonly foo=3
+readonly export bar=4
+```
+
+### Correct code:
+
+```sh
+local foo=3
+readonly foo
+
+readonly bar=4
+export bar
+```
+
+or 
+
+```
+declare -r foo=3
+declare -rx bar=4
+```
+
+### Rationale:
+
+In most languages, declaration modifiers like `public`/`static`/`const` are keywords and you can apply multiple to any declaration.
+
+In shell scripting they are instead command names, and anything after them is an argument. This means that `readonly local foo` will create two readonly variables: `local`, and `foo`. Neither will be local.
+
+Instead, either use multiple commands, or use a single `declare` command with appropriate flags (`declare` will automatically make a variable local when invoked in a function, unless `-g` is passed to explicitly make it global).
+
+### Exceptions:
+
+If you want to name your variable `local`, you can quote it as in `readonly "local"` to make your intention clear to ShellCheck and other humans.
+
+### Related resources:
+
+* Help by adding links to BashFAQ, StackOverflow, man pages, POSIX, etc!