Add tee example to "coming from bash" (#1314)

Add `tee` example to "coming from bash"

Author: IanManske

book/coming_from_bash.md

@@ -29,6 +29,7 @@ Note: this table assumes Nu 0.60.0 or later.
 | `> /dev/null`                        | `\| ignore`                                                   | Discard command output                                            |
 | `> /dev/null 2>&1`                   | `out+err> /dev/null`                                          | Discard command output, including stderr                          |
 | `command arg1 arg2 2>&1 \| less`     | `run-external --redirect-combine command [arg1 arg2] \| less` | Pipe stdout+stderr of a command into less, output updated live    |
+| `cmd1 \| tee log.txt \| cmd2`        | `cmd1 \| tee { save log.txt } \| cmd2`                        | Tee command output to a log file                                  |
 | `cat <path>`                         | `open --raw <path>`                                           | Display the contents of the given file                            |
 |                                      | `open <path>`                                                 | Read a file as structured data                                    |
 | `mv <source> <dest>`                 | `mv <source> <dest>`                                          | Move file to new location                                         |
@@ -55,7 +56,7 @@ Note: this table assumes Nu 0.60.0 or later.
 | `FOO=BAR ./bin`                      | `FOO=BAR ./bin`                                               | Update environment temporarily                                    |
 | `export FOO=BAR`                     | `$env.FOO = BAR`                                              | Set environment variable for current session                      |
 | `echo $FOO`                          | `$env.FOO`                                                    | Use environment variables                                         |
-| `echo ${FOO:-fallback}`              | `$env.FOO? \| default "ABC"`                                   | Use a fallback in place of an unset variable                      |
+| `echo ${FOO:-fallback}`              | `$env.FOO? \| default "ABC"`                                  | Use a fallback in place of an unset variable                      |
 | `unset FOO`                          | `hide-env FOO`                                                | Unset environment variable for current session                    |
 | `alias s="git status -sb"`           | `alias s = git status -sb`                                    | Define an alias temporarily                                       |
 | `type FOO`                           | `which FOO`                                                   | Display information about a command (builtin, alias, or executable) |
@@ -64,5 +65,5 @@ Note: this table assumes Nu 0.60.0 or later.
 | `bash <script file>`                 | `nu <script file>`                                            | Run a script file                                                 |
 | `\`                                  | `( <command> )`                                               | A command can span multiple lines when wrapped with `(` and `)`   |
 | `pwd`                                | `$env.PWD`                                                    | Display the current directory                                     |
-| `read var`                           | `let var = input`                                             | Get input from the user. |
+| `read var`                           | `let var = input`                                             | Get input from the user                                           |