Update bash-extracting_from_files.md

docs/pages/bash/bash-extracting_from_files.md

 # Extracting from files
 
+## Extracting begining/end (head, tail)
+
+## Counting lines (wc)
+
+## Sorting a tabular file (sort)
+
+## Searching pattern (grep)
+
+## Redirecting a command output (>)
+
+## Combining commands (|)
+
+## Replacing pattern (sed)
+
+## Extracting columns (cut)
+
+## Filtering a file (awk)
+
+
+