Remove incorrect letters from san.training.txt

1. Sanskrit does not use all the vowels and vowel marks in devanagari script. Replaced the wrong usage of short e and o by e and o
ऎ
ॆ
ॊ
2. Replaced | and || by । and  ॥ (devanagari punctuation marks)
3. incorrect representation of OM replaced by correct letter  ॐ
4. Remove other punctuation marks unlikely to be found in printed sanskrit texts eg. = ^ etc.