Add issues #25, #26, #27; update #7 and #22 statuses

- #25: $VAR expansion in commands
- #26: Shell abbreviations and user-extensible builtins
- #27: $(cmd) subcommand syntax
- #22: Updated with implementation details (in progress)
- #7: Standardize status label

issues/07-redirection.md

@@ -13,6 +13,16 @@
 `cmd` < "input.txt"           -- redirect stdin from file
 ```
 
+### Alternatively
+
+```lua lush
+`ls -l > output.txt`        -- redirect stdout to file
+`ls -l >> output.txt`       -- append stdout to file
+`cmd 2> err.txt`            -- redirect stderr to file
+`cmd 2>&1`                    -- merge stderr into stdout
+`cmd < input.txt`           -- redirect stdin from file
+```
+
 ## Implementation
 
 - Before `execvp()` in the child process, use `dup2()` to redirect file descriptors
@@ -26,3 +36,13 @@
 ## Challenge
 
 `>` and `>>` conflict with Lua's greater-than and right-shift operators. Like piping, these operators must only be valid in command context. The parser can disambiguate because the left-hand side is a command expression.
+
+## Alternatives
+
+- Although shell redirection isn’t available, simple redirection can be achieved using the `io` library.
+
+```lua lush
+file = io.open("OUTFILE.txt", "w")
+file:write(`ls /`.stdout)
+file:close()
+```