chore: add issue template & auto stale issues and pr

[imbajin]

No description provided.

[codecov]

Codecov Report

Merging #64 (ae58396) into master (10b347e) will increase coverage by 6.91%.
The diff coverage is 89.90%.

❗ Current head ae58396 differs from pull request most recent head 8bb8481. Consider uploading reports for the commit 8bb8481 to get more accurate results

@@ Coverage Diff @@ ## master #64 +/- ## ============================================ + Coverage 80.89% 87.81% +6.91%  - Complexity 956 2083 +1127  ============================================ Files 105 225 +120 Lines 3230 7083 +3853 Branches 282 576 +294 ============================================ + Hits 2613 6220 +3607  - Misses 483 566 +83  - Partials 134 297 +163 

Impacted Files	Coverage Δ
...hugegraph/computer/core/aggregator/Aggregator.java	0.00% <ø> (ø)
...aph/computer/core/allocator/RecyclerReference.java	100.00% <ø> (ø)
...idu/hugegraph/computer/core/combiner/Combiner.java	0.00% <ø> (ø)
...computer/core/combiner/DoubleValueSumCombiner.java	100.00% <ø> (ø)
...h/computer/core/combiner/LongValueSumCombiner.java	100.00% <ø> (ø)
...raph/computer/core/combiner/OverwriteCombiner.java	100.00% <ø> (ø)
...graph/computer/core/combiner/ValueMaxCombiner.java	100.00% <ø> (ø)
...graph/computer/core/combiner/ValueMinCombiner.java	100.00% <ø> (ø)
...idu/hugegraph/computer/core/common/SerialEnum.java	85.71% <ø> (ø)
...puter/core/common/exception/ComputerException.java	92.30% <ø> (ø)
... and 341 more

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