pipe input to minishell; expansion of local and exported variables; debugged echo option

[jdagz28]

output is the same as intended. (from bash)

jdagoy@GS63VR-7RF:~/Documents/19/Minishell$ echo "echo hello world" | bash
hello world
jdagoy@GS63VR-7RF:~/Documents/19/Minishell$ 

and from minishell passing to higher minishell shell level

jdagoy@GS63VR-7RF:~/Documents/19/Minishell$ echo "echo hello world" | ./minishell 
hello world
jdagoy@GS63VR-7RF:~/Documents/19/Minishell$ 

Limiting edits to affected files to minimize conflicts during the merge. However, restructuring the flow is necessary for coherence and improved understandability.

what change: in main

• not using argc, argv

in shell_init

• added bool inline mode in shell struct
• removed parse() for ast; instead initialized to NULL

in shell_prompt

• added conditional for incase inline mode
• if inline mode then use get_next_line

[jdagz28]

debugged expansion of local and exported variables

[jdagz28]

debugged echo. handles multiple valid option -n. executes normally with option --- disregards the succeeding valid options in the argument