Read only access to stored procedure contents

You can grant them the VIEW DEFINITION privilege to those procs.
See here for what this privilege does.

You can apply VIEW DEFINITION at different scopes:

• Server
• Database
• Schema
• Individual entities (e.g. a proc, a function, a view)

You can also use a query to generate a script for many procs.
So if you have a user Bob:

SELECT N'GRANT VIEW DEFINITION ON '
    + QUOTENAME(SPECIFIC_SCHEMA)
    + N'.'
    + QUOTENAME(SPECIFIC_NAME)
    + N' TO Bob;'
FROM INFORMATION_SCHEMA.ROUTINES
WHERE ROUTINE_TYPE = 'PROCEDURE';

that will give you something like this, which you can then run:

GRANT VIEW DEFINITION ON [dbo].[aspnet_RegisterSchemaVersion] TO Bob;
GRANT VIEW DEFINITION ON [dbo].[aspnet_CheckSchemaVersion] TO Bob;
GRANT VIEW DEFINITION ON [dbo].[aspnet_Applications_CreateApplication] TO Bob;
...